C4 Corvette LS/ 6-speed swap
On another note, its good to see the garden doing well. My wife and I have been slowly adding to our .625 acre property and have multiple garden beds with lots of tomatos, cucumbers, beans, greens, peppers, and potatos. Along with a few herbs, and we built some hoop houses to grow some winter stuff. 1/2" pvc works well for the hoops. We want to be at least a little less dependent on the supermarkets. At some point I will saddle up and go hunting with a friend who has 3 freezers full of fresh meat. But anywho, good to see another solid healthy garden.
Yes, i'm real happy that we got the shifter worked out. Now I just need to decide on a shift **** and get a new shift boot made as my old one was getting a bit ratty.
Can't decide if I should go with a nice custom TwistedZ shift ****, a C5 6 speed **** or an early C6 6 speed ****....
They also got the oil cooler mocked up. Were going to try putting it between the rad and the rear cooling fan as there is just enough space to sandwhich it in there. Its not an ideal location as the cooling effciency will be lower behind the radiator than if it was getting fresh air but its better than nothing. The cooler is a dual core 9×13, we oversized it on purpose knowing it wouldn't be mounted in an idea location, so hopefully our preditions about how much cooling it will do are correct. If I find oil temps are getting high I can always remount it somewhere else but this way avoids hacking up the front of the car/air dam and should still provide some oil cooling.
The mounting bracket was made out of a piece of sheet aluminum that they formed by hand. I might have them move the cooler so its a little more centered on the fan, but I need to see it in person before deciding.
Last edited by DMITTZ; Jul 6, 2020 at 12:36 PM.
For the fuel pump I went with an Aeromotive 340LPH in tank pump (E85 compatible), its overkill but it was in-stock and gives some head room for future mods (can support like 700+hp). Also got some new hardlines and a TON of other fittings and 6ft -8AN black braided fuel line. The bad news is 4 fittings used to couple the GM fuel rail to the -8AN line are on indefiniet back order (maybe covid related???)
So we've got to figure something out there, the guys at the shop said they'll try and find some other options as they were hoping to do the fuel system soon... hopefully they can figure something out for the fittings.
I also got a neat product from Earl's that will allow me to adapt my stock clutch master to use a -6AN braided hose and then connect that hose to the F-body T56 slave.
i've informed the shop, they'll proabbly need to upgrade the wiring to the bigger fuel pump, which they are planning to do.
Also while I was at the parts store, I happened across the half-decent looking shifter **** and decided to buy it. I may get something custom made in the future, but this will work alright for now.
I've got a ACDelco C5/C6 fuel filter/regulator that i'll be picking up tomorrow from a local parts store.
However, my friend called to give me an update yesterday evening:
C-Beam:
they got the C-beam mount figured out, its just tacked together under the car right now but once it's finish welded they will send me some pictures and they have assured me it is plenty strong.
Oil Cooler:
The oil cooler has also been fully plumbed.
A/C:
The A/C kit has been test fit and mocked up. They had to do a little grinding on the bottom of the bracket but it now fits, we just need to get some custom A/C lines made to finish the plumbing on it. They did say they found a belt for the whole accessory drive and tested it and so that is done also.
Power Steering:
The power steering has been a bit of an unexpected issue, however the shop has plumbed some new braided AN lines to to replaced the stock lines, they have been having a hard time clearing the pulley on the pump, but they think they have found a Earl's fitting thay will work and will send me the part number of it this week so I can pick it up.
Radiator hoses:
I'm told they have got a lower rad hose that will work and mocked it up, the upper rad hose still needs to be dealt with. They also have the heater hose fitting for the water pump but have'nt installed them yet.
Fuel System:
We are going to have to do a bit of a rethink on the fuel system as the -8an fitting we need are not being made until further notice by any company that we can find.

So i've got to return some stuff and we are going to switch to using -6an stuff since we can get it.
The shop still feels -6an will supply enough fuel for the current setup they were just going -8an to give lots of extra capacity in case I wanted to go forced induction in the future, which I'm not planning to do anyway. So we'll switch to using 3/8in hardlines and -6an (vs 1/2in hardlines and -8an), but will still use the bigger 340lph fuel pump.
Shift ****:
Apprently there was a miscommunication about the thread size we needed on the shift ****, so i've got to exchange the **** for something similar with a different thread size or buy an adapter.
That's all the updates i've got for now.
Last edited by DMITTZ; Jul 12, 2020 at 02:07 PM.
The Best of Corvette for Corvette Enthusiasts
Last edited by DMITTZ; Jul 12, 2020 at 03:46 PM.
The plan for the air intake is to reuse my SLP tri-claw intake with this duct behind it. We will then put some sort of connector pipe behind this duct and then use the rear air intake duct from a LS2/3 C6 Corvette to connect to the throttle body.
The rear intake duct should be arriving anyday, then the shop can make the adapter pipe.
Hopefully were just about there for the 'plumbing' these fittings really add up in a hurry!
The bad news is USPS seems to have lost a package of my parts with my antenna motor, gas tank straps, and a bunch of other odds and ends. I've opened a claim with them and they said they will investigate and let my know within 60 days their finding
I Got lots of pictures for you guys.
Here's the offset shifter...
Here some pictures of the Beam brace:
So The C-beam adapter is a 2 piece design. The 'inner' part is 3/8 steel and connects to the tail housing bolts on either side the trans, and slips inside the C beam, with the C-beam bolts running throught it. (see above picture)
The second piece is 1/4 steel plate that attaches to the usual cross member attachment point on the trans and then is bolted to the bottom of the C-bean. Together I think it should be pretty strong. (proabbly stronger than the tail housing on the transmission).
Air intake (still in progress):
The rear intake 'duct' is 4in, the front 'duct' is 3.75in so they will have to use an expander pr shrinker on the piece of S/S exhaust pipe to adapt the two. There is only about 2 inches between the two ducts so comestically I think it will look ok, (about the same as a MAF).
Power steering plubed using a Earl's special fitting to clear the PS pulley. Its really close but it clears! The power steering hose was replaced with an AN line.
Throttle cable and fabricated bracket:
The throttle cable is able to be snaked under the coil covers and should look very factory.
Fuel system is plumbed from the fuel filter to the engine now. The pump and lines to the filter still need to be done.
Water pump heater hoses are plubed using 45 degree fittings:
For the A/C the compressor and bracket fit, but the shop thought getting the lines to connect would be pretty tight against the wheel well.
So they are going to clock the compressor in a different orientation, to give more room for the lines, and trim the uneeded part of the braket off. A support piece will tie the top ears of the compressor to the bracket.
We will still need to have some custom A/C lines made.
The oil cooler is totally plumbed now also:
Well'll proabbly throw a nice insulated sleeve over the lines, to protect from the header heat.
That's all for now:
Do whatever you can to keep the weight off the car. Ceramic coating the headers will do a lot more than you think. I wouldn't worry too much about wrapping the headers or wrapping lines that are more that an inch or two away. The under hood temps of my car are amazing compared to my previous hot rods that had manifolds or uncoated headers.
I just got done with phase 1 race car mods. Dropped ~125lbs and modified the exhaust to 14" body 3" inlet/outlet FlowFx bullet style mufflers. I had quite a bit of fun gapping cars last night that were gapping me 3 weeks ago.
Do whatever you can to keep the weight off the car. Ceramic coating the headers will do a lot more than you think. I wouldn't worry too much about wrapping the headers or wrapping lines that are more that an inch or two away. The under hood temps of my car are amazing compared to my previous hot rods that had manifolds or uncoated headers.
I just got done with phase 1 race car mods. Dropped ~125lbs and modified the exhaust to 14" body 3" inlet/outlet FlowFx bullet style mufflers. I had quite a bit of fun gapping cars last night that were gapping me 3 weeks ago.
Keeping the weight down definietly helps, our C4's are pretty light compared to today's FAT performance cars and it shows when you put a proper amount of power in them.
Last edited by DMITTZ; Jul 18, 2020 at 06:21 PM.
Last edited by Krusty84; Jul 18, 2020 at 09:54 PM.
The #8 coil has lots of clearance to the hvac box, with the spark plug wire installed there is about 1/2in between the box and the wire. Lots of room to access the spark plug from below if needed too.
Last edited by DMITTZ; Jul 19, 2020 at 05:28 PM.
Back when I put the SLP intake on my car, I just mounted it by screwing it into the fiberglass radiator shroud. That ovious isn't a good way to mount it. The reason I mounted it that was was that since it was for a late C4 my early C4 shroud didn't have to mounting provisons for it.
So I decided to try to remedy that today.
I figured out these metric bolts I had laying around fit the original GM air intake hold down nuts. So I cut the threads on the bolts quite a bit longer (M6×1.0)
Then I cut the threaded portion off in the bandsaw and screwed it into the hold down nuts with some Red lock-tite...
Next it was time to make the part that mounts into the shroud. So I chucked up some 1/2in round stock in my 1953 South bend 9 lathe.
The idea is this part will go through a drilled hole in the shroud and be JB welded to the shroud and the 'shoulder' will stop it from pulling through.
Next I drilled through the part and cut some M6x1.0 threads.
I'll try to get the second one made this week and painted then hand them over to the shop.
Last edited by DMITTZ; Jul 19, 2020 at 09:45 PM.
I finished machining the other CAI hold down and dropped them off at the shop.
I had a quick look when I was there at the progress the guys had made.
The connector for the cold air intake is done:
We will still need to paint or powder coat it black and get another clamp.
The Lokar throttle cable is now connected to the pedal, which apprently required removal of the steeeing colomn to gain access...
The fuel System is plumbed, including new hardlines. The fuel pump still has to be installed and wired, but we need to get a new fuel sender first.
The shop will put some clamps on the lines to keep them away from the sway bar. Once the rear end is back in the car.
Speaking of which, while I was at the shop I picked up some parts.
My Dana 44 currently has a 3.07 gear. I'm planning to take it to a driveline shop and have some 3.73 gears swapped in.
I will also take the driveshaft to the driveline shop to be shortened 2.5inches:
The headers are also now ready to go out for ceramic coating. The shop smoothed out some of the welds, relocated the oxygen sender bung rearward a couple inches so it will get a better read of all the cyliners. Additionally they added a V-band to the collector.
Additionally, while we have the rear facia off i'm going to get it repainted as it has a small crack in the paint and some chips low down behind the wheels.
I went ahead and removed the side marker lights, reverse lights and trim pieces. Sadly most of the old rusty bolts broke off so I'll have to purchase a bunch of new parts.
From what I can tell the car has been repainted once (in the same color) but they just masked off the trim last time
. So this time i'm going to get them to sand it down throughly and paint without the trim etc... (the proper way), i'm going to let the body shop remove the 'Corvette' name as it seems to be both rivited and taped on and I don't want to damage the urethane getting it off.Here's the rear facia ready to go out for paint:
Now I just need to talk to some body shops and get some quotes.
My Friend that owns the speed shop, his wife is due to give birth in about 10 days. He's planning to get a little more done on the car before that, but with my blessing is planning to take 2 or 3 weeks off and close the shop so he can take care of his family when his baby arrives so there may not be a lot of progress during the next month, until he gets back to work. However, that should give me time to get the headers, rear end, driveshaft and rear facia dealt with and I'm also going to order up the Dakota digital box(s) for the tachometer and speedometer so everything is ready to go when he gets back to work.
Last edited by DMITTZ; Jul 26, 2020 at 02:02 AM.












