63mako...just curious on your suggestion of the cam being a hydraulic Tappet vs. full roller?

 

The cam link above is a hydraulic roller. I would never recommend a flat tappet cam in a performance build unless budget will absolutely never allow the upgrade unless you use a flat tappet. If the extra $3-400 is to much go flat tappet or better yet wait and save another 3-400 bucks. You asked for my opinion and recommendations. The links I posted are the parts I would use if I had your car and wanted to upgrade the stock engine. The combo I posted will match your gearing, trans and each other well and get you around 425HP for under $2500. If you want to cut cost you will lose power period. There are also likely combo's that will make more peak hp at a sacrifice of streetability, manners or bottom end- midrange torque. There are literally thousands of possible combinations that will work in your car. If you post on here you will get a lot of recommendations and opinions. Some good, some bad, some horrible!

If you go flat tappet that power # drops. If you go cheaper heads that power # drops. If you go less compression that power # drops. A well matched combination with power in the rpm range you can and will use it is the key not just highest peak power numbers.

Every street engine build involves a series of compromises in the design stage. Too radical, too expensive, power to high of rpm, not enough high rpm capability, cast bottom end vs forged, great heads vs good heads vs cheap heads.170 cc runners vs 227 cc runners, high compression vs low compression and it goes on and on.
My friend Motorhead has a great quote Fast, Durable, Cheap. Pick 2.

 

Great advice, much appreciated !!

 

As a footnote, the Howard's cam specified is nearly identical to the specs of the retro-roller I got from Comp. For another $350, you can get the complete Comp K-kit with all-new valvespring kit, timing set and cam button. All matched parts took the guesswork out of my conversion. If you get new heads with the roller-spec valve spring kit, then getting all of the extra parts in the kit is a waste. I checked the Comp cam/lifter kit @ Summit and it is $115 more than the Howard's cam/lifters. I do note the k-kit seems underpriced since it includes timing, pushrods, button and the valve spring kit.... seems they are encouraging the Comp kit purchase over just the cam/lifters since kit is just $235 more than just the Comp cam/lifters.

 

63mako...
I was doing more homework / cross ref of my casting numbers on my rear...I do NOT have 3.73's as the PO told me.... I have code OJ whihc is 2.87:1...
So how does this now factor into your build specs we have been discussing? ** I assume more $$ for me LOL **

 

The PO might have changed the gearing if he told you 3.73 gearing as that is an aftermarket ratio. 3.70 is stock. Check actual ratio by raising the rear, mark and turn the driveshaft. After the halfshaft has turned 1 turn how many turns of the driveshaft? If it is just under 3 you have a 2.87. If it is 3 3/4 you have 3.73. If it is 2.87 Easy fix. Change your gears. Tough to build true performance with those gears behind an automatic but it can be done just not as high of HP or operating range.

 

If you have the 2.87 gear and don't want to change it don't mill the heads and drop to this cam:
http://www.summitracing.com/parts/hr...make/chevrolet
Leave everything else the same. That gear is really not conducive to performance. Engine will run out of power at lower RPM and less HP but will pull strong bottom end and midrange up to 5000. Compromise.

 

Ah I see and then I guess this does give room for "later down the road" of new gears, mill heads, cam swap, etc. like you said compromise now but leave door open for more later
Really, Really appreciate the info!!!

 

I was having the same issues: How to get more horsepower out of my 76. After pricing new cam and heads and the work involved in installing them I decided to pull the motor and go with a crate engine from Blue Print Motors. Im currently installing the motor now and hope to have it on the road by the end of next week. I decided to rework the transmission so it won't cause any issues down the road. The motor i purchased is BP 35512CT1 298717. It was specked at 375 hp but the dyno sheet came in at 417 hp. The motor was under $3000.00 and came with aluminum heads and a 4 bolt main. Cost for cost it would have cost me about the same to do the heads and came work. Now I can rebuild the original motor at my leisure and still play with my car. I will let you know how the new motor works out. Good Luck

 

Thank you for your progress update , I'll check out your build - sounds really nice. You should def start a thread with some images and progress. We would love to see it, helps with the motovation as well

 

That engine makes good peak power but a 230 duation @ .050 cam and 195 cc heads in a 350 combined with your gearing and auto trans will not be a good match. It needs a 2000-2400 stall convertor and is also externally balanced. Just a heads up. HP is great as long as it is in the RPM range your car weight, gearing, convertor and trans can use it efficiently.

 

We are a nosy bunch here, and I am sure that I am not the only one who would like to hear more about your project. What tranny are you running, what are the differential gears, torque coverter stall speed, (if applicable) what rpm does your horsepower peak at? If you could post the dyno results we would love it. Don't answer here, though, it's too far off topic, start a new thread, OK?

Scott

 

lots more good stuff in here..........what to do, what to do

Fast, durable, cheap. Which two should I pick?

 

Hi started new thread called new motor install let me know what you think.. thanks

 

Fast and cheap!

Scott

 

women and cars

 

What would you do to build the bottom end? It does make sense to start here. The rear main seal is leaking and getting worse the more I drive it. I was wondering if I should get another block and rebuild it or get a new block.

 

Theres usually nothing wrong with building the original block provided you get it checked first and you not shooting for too high a power level. If having the original numbers matching block is important you might consider moth balling it and start with a 4 bolt main block that is roller cam compatible with out retro fit. So in my opinion it comes down to how much power are you plannig.

 

...and how much $$$ you're planning...

 

i will once again be taken to task for saying this but, i don't see any L-82 c3 becoming exceedingly valuable in our lifetime. your stock L-82 bottom end is as good as chevy ever built, so unless the 25 - 30 ft lbs for a 383 is a must , just rebuild it.

with mako, your too close to 325 h.p now it isn't funny .

i have an L-82 , aluminum 64 cc heads, 1.6 rockers , headers air gap intake 750 quick fuel double pumper. how much horsepower? i don't care.
its amazingly quick, very drivable if i drive it carefully the mileage is decent. and it pisses off a lot of the new cars out here.

no mater what you do select you components carefully .

i agree a roller cam is the way to go, but we have a local camaro running around with a 383 with a thumper roller and mine beat his car so bad i thought he would set his car on fire. good luck.