Ifvyour frame was rotten enough to bend when you jack it up it would have collapsed and had the body pinching the frame on either end. Plus you would notice a significant driving issue plus body noise....i ve seen truck ladder frames rusted so badly the center sectiins were all gone and it still held together.....Another one i wish i had a pic of, a truck in Ketchikan rotted in half and the poor guy literally stacked the frame at the break and welded it together....it was hilarious but he drove it for years that way....

 

My frame is a new england frame. Lots of big chunks of the inside of the frame coming out of the drain holes near the kick ups and center rear parking brake return spring...i try to avoid potholes which is a lost cause and go slow across railroad crossings, but with my tight suspension its still really rough. If my frame hasnt collapsed with all that i truly doubt yours will if you havent noticed any holes or soft spots you can stuff a pencil through...

You should also invest in a quick jack if you are going to do your own work...its worth it. Best thing i bought besides a 5 speed

 

And at this point with your car you are now a mechanic, not an engineer. Its already been designed....relax a little and just fix whats wrong, dont try and re-engineer it. You work hard 40 plus hours a week, give your brain a break and just turn wrenches..All you have to ponder is what caused your issue you are fixing.

Unless you are going with some of the fancier 4 or 6 link rear suspensions. Definitely look up peoples experiences with those. A few designs dont work as advertised.

 

You're a mechanical engineer? Congrats. So am I. I'd bet there are quite a few on this forum. Then you've got machinists, mechanics, techs, and plenty of other professions on here that "think in technical terms". So no one really cares.

If I'm going to appeal to authority, I'm going to appeal to the original engineers. I can do my own calcs to check roughly what to expect if I want to nerd out about it, but they are the ones who actually designed the car. They analyzed it for all of the loads it was expected to see, including being up on a lift. These cars were lifted from between the wheels their entire regular service life. If they were going to bend, they would have done it in 1968 when the first car rolled into a shop to have tires or brakes changed. Or hell - way back in 1963, since its pretty much the same frame. As for corrosion, I've got a similar experience as Rescue Rogers there. I've lifted my car from behind the front wheels, and the kick-up area of my frame is pretty damned close to non-existent at this point from rust. It didn't break in half, it didn't delaminate the fiberglass...its in the same condition as it was before I lifted it. Again. And again. And again. Hell I've had the thing entirely up on jack stands only in the center of the car - with a non-existent kickup area of the frame! Talk about a hell of a bending load on a "weak" structure!

Rescue Rogers is also correct that, as you are now a mechanic on this particular car, it is your sworn duty to curse the engineers who designed this thing and made it such a PITA to work on...I don't make the rules, I just follow them...

 

the interior electrical designer for placing the fuse block as far forward as possible is top of that list....ohhhhh boyyyyy is it hard to get to

 

oh and by the way you are probably new to your 68 so there are a lot of 68 only things you should be aware of.....or atleast 67-68 things. There is a list somewhere but I will try and remember all of them, atleast the big ones excluding things like turn signal covers and things like that. I have changed a lot of things in my car so some 68 only knowledge is lost to me as I have forgotten more and more every year

starting at the front depending on when your 68 was built early 68s differ from later 68s...lots of revisions....some of these things may drift into early 69

1. headlight door covers...early models are smaller than the late 68 and 69s
2. headlight surrounds are smaller, you will notice that later plastic covers are wider and have an obvious gap.
3. THe early ones were metal not plastic and you will see cracks on the passenger side bezel at the front corner
4. I wont go into the shields or the grill. Havent had to look for parts for it so I dont have info on them
5. the front king pins are the same as 67 and have a smaller diameter bearing than a 69 or later
6. these kingpins are also setup for 7 inch rims..8 inch rims and wider tires may cause the tires to rub the frame at the rear at full lock
7. 68s were designed for 7 inch wide rims
8. the steering box has a different spline than 69 or later. I believe its the same as 67...not positive
9. small block 4 speed radiators have a double pin bottom mount system, they are a bit wider than 12 inches apart and point straight down, on top is a horizontal bar that is grabbed by a bolted in mount
10. automatics and big blocks used a wider and thicker radiator that have the typical cradle mounts top and bottom at the tank seems
11. the radiator supports are narrower than 69 and later and are mounted on top of the frame and crossmember. The big block and small block are generally not made with both small and big block mounts, but I did see one that had both, not sure if it was for a later production run or and aftermarket support. A/C / automatic cars have more holes for the evaporator/ cooler
12. 68 alternators are extremely under powered...they may have used them in 69 but they are somewhere around 63 amp...and have an external regulator...If you are wanting to upgrade your lights there are wiring adapters to make the 2 plug charging system a single plug with the stock wiring and is probably good up to 80-100 amps. Anything more taxing like electric fans along with a bigger alternator and original 50 y/o wiring and you will want to add a bigger wire from the alternator to the starter lug all other wiring coming from the starter can remain the same in this instance.
13. the headlight vacuum system has one actuator relay in the center
14. the wiper door actuator is inside the passenger side fender and is difficult to see never mind replace
15. the wiper motor is 68 only and has a switch that is negative switched. Do not try to rewire the switch...the owner before me did that...all smoke no fire....I bought my last motor from Lectric Limited and it says do not bench test on the box...there are some bench testing procedures for your current motor while its in the car...it can be a hassle with all the safety interlocks
16. the 68 wiper system has less vacuum components than later years
17. the motor also has a parking switch relay that is on until the motor is parked and the system shuts off totally. You have a wiper override switch under the dash that is a rotating ****, just a one degree turn is enough to disengage the ground contact and it will keep that parking relay energized which will put a slow drain on your battery. Its in the AIM and was changed in 69
18. the gauge colors are generally green tinted
19. the center console has a smooth surface versus later years that have a pebble finish for glare...there are A/C console differences as well that I dont know fully
20. there is also things like no on off control for vent *****, just turning them to block the flow, no inside door pull handles, steering wheel is a plastic wood grain
21. the ignition is obviously in the dash so we also only had a regular column or an extending column similar to a 67..no tilt and later columns wont work with the 68 steering box or rag joint
22. obviously the push button door opener and lock
23. the windshield stainless trim is different but I havent replaced any so no sure what or why
24. the convertible top receiver is different on the windshield as well
25. the hood latches are different than later years. They way they mount to the hood isnt the same and have read that the hood itself is different in that way but havent had to figure it out
26. the floor is fiberglass, hence has different seat sliders and has a 250lb weight limit
27. THe seat belts are partial retractors and are mounted under the seat
28. the center console has seat belt holder slots
29. headrests were and option, some of the sliders are inside the seat back but does need some others to make them usable
30. the shoulder belts are an option but the anchor holes are there on the rear wheel wells
31. shifter has an upper rubber shift boot as well as a rubber lower, later cars had a leather upper boot
32. obviously no stingray trim or chrome gill trim
33. I have a convertible so I dont have any T top knowledge
34. the convertible top rear deck top latches are 68 only and require a very narrow pin and mount on the top. Later years are thicker and have different latch
35. the exhaust tips are round not square.
36. Obviously the backup lights are seperate on the bottom pan
37. the earlier frames dont have the kick up support trusses so the frame flexes a bit more in turns and over bumps
38. Early 68s have a notorious habit of the passenger side hood releasing because of this and can be adjusted to have it less of an issue but it is still there on heavy bumps
39. the rear trailing arms have shims that have through holes instead of notches so they have to be disassembled completely to adjust instead of just removing the cotter pin, loosening the bolt and sliding them out
40. the trailing arms also have the parking brake tab on the inside instead of the top so using an 8 inch wide rim may or maynot contact this tab. I had a 1/16th inch gap......not much at all, 17 inch tires clear easily...wider tires may contact the rear spring bolt

Im sure there is other things, just tried to get what I remembered off hand

 

Forgot 68 early seats had the low release latch. A real hassle to get to on the passenger side as its on the driver side of the seat....tops and bottoms are basically all drivers side seats

 

When I first got the car I thought somone had installed a drivers seat on the passenger side due to this anomaly!

My buddy warned me about some of the idiosyncrasies of a 68, looks like he forgot a couple hundred things..😃

Luckily this stalled project is mostly complete/correct w good options (L79, 4SP/PS/PB/AC) I believe the previous owner

was a checkbook mechanic who ran out of time/money/patience/ambition.

FWIW I think if it’s taken to a shop and they’re not Vette experts you may as well just do the work yourself as you have just

as good a chance as getting it done right and they don’t care as much about your car as you do.

 

Exactly...I do all my own work because of that. Front end alignments are difficult. I set mine up and it doesnt wear at all but I want a pro to do it to be sure. It sounds like you got a great options package as well. Mine was L79 power steering only...really would llike A/C anbd definitly adding power windows. From the prices Ive seen the factory A/C dash parts for a 68 are hard to find so therefore valuable. Are you going to revive your stock system or upgrade to the vintage air. Is your car a T top or vert?

 

Wiring Diagrams!!!! I have a color coded one I found on ebay that has the correct color wires so its easier to trace... I also bought a set of OhSoEZ wiring diagrams from DocRebuild..They have all the correct plugs on the ends so if something is unplugged you can figure out what it is for There is 2 sheets Look at his stuff online but order on the phone. He is very anti NCRS. He had a lot of folks ripping off his stuff back in the day and had some other issues so just be aware of that. Super nice though. He has some great parts and the vacuum hoses are the right diameter and actually fit better than anything you will get from the regular suppliers. His radiator seals are perfect as well and cover all the weird gaps. There was one I had that I couldnt find where it belonged until one day when I was putting a bigger air dam on. Its actually in front and under the front frame area. His stuff is more accurate to the original stuff than other stuff I have bought

 

Are you going to revive your stock system or upgrade to the vintage air. Is your car a T top or vert?

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Dunno about the AC yet, haven’t got that far into the car, there’s some underhood wiring fuckery I need to undo
and then I am going to cross my fingers and turn the AC on and see what happens!

Car is a coupe btw..

 

Good luck with the underhood wiring . IF you have to replace stuff there is 2 harnesses under there, the headlight harness and the engine harness. If you get rid of one or the other keep it for the plug ends I made a wiper motor test setup with the old plug ends so its easy to hook up.

I also forgot the brake light switch is 68 only as well and the way its mounted and such...

I get my harness stuff from these guys. Their switches are a bit better than most but again...not perfect but about the best you can do lately
https://www.lectriclimited.com/vehic...ke/21/model/65

 

>>>>>>>>>>>>>>>>>>>>>>

Thanks for that info, will definitely be consulting when it’s time for the wipers, someone really took good care
of this car years ago but then Bubba got ahold of it and it’s been keeping me busy just examining the car
and some of the errant fixes and trying to understand why some things were done the way they were.

one example: The temp sending unit is installed into the port on top of the waterpump and there appears to be
a plug where it should actually go into the head on the drivers side.

it works but of course is reading the temp at the absolute coolest part of the cooling system, why on earth that was done is beyond me so I plan to gently try to back that plug out of the head and get the sender back to its rightful location.

Just a bunch of hack stuff like that under the hood I have to unravel, but it does run very well, does not run hot, doesn’t leak any fluids and track straight and true with no rattles/clunks/scary noises so that makes me happy….

again, thx for the info, this is my first American car restoration and the forum and its members have been of great assistance!

 

congrats on a great sounding car. you are correct with the port on the drivers side head for the temp sender. If your fiber optics arent working look for splices...my PO had cut them and used those blue crush to crimp splices to get them to work...guess he didnt realize fiberoptics is a glass strand...LOL. Sounds like both of our previous owners were just trying to flip the cars...MIne had lots of stuff like that he fixed with whatever was handy out in the garage random screws and bolts.. Lots of drywall screws and galvanixed lag bolts...if it didnt fit he would either use a bigger lag or throw a metric bolt into it.....ridiculous

 

If your fiber optics arent working look for splices...my PO had cut them and used those blue crush to crimp splices to get them to work...guess he didnt realize fiberoptics is a glass strand...

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>

mine do not work, I read up a little on them, very interesting technology for 1968, they are on the ‘check’ list along with a million other things..l

luckily the headlights do work, albeit one comes up slower than the other, all dash lights/gauges work except the clock
and odometer, all outside lighting functions correctly except no backup lights, courtesy lights/middle rear compartment lights not working, just a bunch of interesting and amusing issues to work through over time.

Bought it last summer after a long search, but life got busy with relatives, holidays and some remodeling so just now taking long looks at the different systems and doing a lot of reading and forum thread searching, thx for your help.

 

Enjoy the the corvette journey
....its has its ups and downs but the upsides are always great...

 

This thread got way too tldr...

Everything ya need to know in post 3 and 5. Those who worry do so for no reason. The car sits on four points being the wheels most of its life...without frame bending etc. As said...these are stout frames of steel made when quality mattered....more.