Hey guys i just bought a 1981 vette and im wondering if it’s even worth the hassle to delete the computer. I am going to get a good set of long tubes im looking at the hooker 2456-1hkr i want long tubes im just a tad worried of ground clearance and fit for that matter. Then im going to get a full exhaust behind those. My issue is in the future would like to add a cam and high flow heads. If im going to be upgrading the heads cam and exhaust should i delete the computer and get a new carb intake and distributor. I have a manual and this weird Vaccum stuff is confusing me im somewhat new to this. So im looking for recommendations on all the parts mentions. What people like headers wise(want long tube for the sound) exhaust wise heads cam carb and distributor recommendations are all welcome and appreciated and if deleting the computer is even worth it.

Thank you!

 

81s are a bit odd. If it runs right now, go drive it and enjoy it! If you live in California, that's probably all you can do.

If you have a long list of mods you want to do over time, you will need to replace the carb and stock distributor. That will let you a top-end rebuild that will really wake up the car. But you'll still have a 42 year old low-compression L81 engine. Once you add up all the little things over time, you may find (like many have on this Forum) that an engine swap is more cost effective. You can drop an LS-based truck engine in there and beat the HP of all of your proposed mods, plus gain EFI and a stronger platform for more mods.

So, go drive your car before you decide! And when the Forum lets you, please post some photos! If you absolutely have to spend money on it right now, replace your tires if they are more than 6 years old, and consider doing some suspension and brake work.

You mentioned a manual. Is it a 4-speed? Or a year-specific Corvette shop manual? Those, plus the owners manual and assembly instruction manual are the only manuals worth having.

 

I’ve used the Flowtech 31106 headers on multiple C3 builds and they fit great. To dump the computer and make some power you’ll need heads, cam, intake, carb, and an HEI distributor. With the 4spd it will be a different car.

 

It is indeed a manual a Saginaw four speed

 

And okay the route we wanna go is sidepipes here. Two questions is there a way to keep the computer happy while running sidepipes? Because I’ll have to remove cats so is there a sidepipes with bungs for o2 or is that just not possible and I have to do the full CCC delete if I want pipes so distributeor and carb. Also when I do the CCC delete I’m gonna get a CEL correct? Is there any way to solve that?

 

You can weld a bung for an O2 sensor on side pipes.

 

You can keep the ECM of a Gen III or Gen IV LS engine happy with sidepipes.

Otherwise, you will likely need to revert back to 1980 specs, with a new carb with an electric choke (and intake, possibly, depending on what you get), and a new 4-pin HEI distributor with vacuum advance. Or go with Sniper EFI, but that route might cost more than an LS swap (no kidding!)

Are you sure it's a Saginaw 4-speed? What's the suffix on your engine stamp pad? Perhaps your car was originally an automatic that someone swapped.

4-speeds are very rare in 1981, 13.7% of total production, but all of them came from the factory with an aluminum Borg & Warner Super T-10 4-speed.

https://corvettec3.ca/engines.htm

 

i might be able to get that number for you later when i purchased it it was listed as a 1981 all numbers matching with the Saginaw but not totally sure

 

You haven't bought it yet? Don't pay a premium for a "numbers matching" car if the current owner doesn't know what that means. Especially if you just intend to mod the car anyway.

In addition to the engine suffix, check that the partial VIN is on the engine stamp pad, and check that the exterior and interior match what's on the trim tag. That is the bare minimum for "numbers matching".

https://corvettec3.ca/vin.htm
https://corvettec3.ca/interior.htm

If you can get the VIN, it might be worth getting the dealer invoice from GM for $50-, though that might take a few days.

https://www.gm.com/heritage/archive

Finally, read post 107 here, and know the rust trouble spots to check. Bring a screwdriver, and don't buy a rusty car.

https://www.corvetteforum.com/forums...orvette-6.html

 

i got it already i was just saying i have it stored so i cant get the number. I can try and find the vin buried in my desk though. I traded an 86 Camaro and a fully custom hard tail for it got a damn good deal

 

Ah, no worries then. It's worth a lot (to nuts like me), because of the 4-speed. I'm looking forward to seeing some photos when you get back to it!

 

man ive loved them ever since i was a kid ill get you some pictures its silver with navy blue here are some pics yeah didnt know how rare the four speeds were kind of lucked out. I’m so excited to work on it over the winter. I plan to get some Doug’s headers and side pipes and then an edlebrock intake manifold and 650 carb kit with a new distributor that should wake her up a bit then i can get rowdy

 

Nice! That should clean up well and be a super-fun car.

If you haven't bought anything yet, @Jebbysan posted his recipe here in post 3.

https://www.corvetteforum.com/forums...-recipies.html

That's a good one to follow, or take some leads from if you stick with the SBC. Of note, the Holley Truck Avenger carb is likely to do better for you than the Edelbrock.

But I can't recommend sidepipes highly enough. If that's the look you are after, go for it! Just warn your passengers not to burn themselves.

 

yeah im gonna do the pipes they look too cool not too. And with that truck carb what is better about it over edlebrock? I proably wont be putting new heads on it for a long time so wouldnt the CFM of that truck carb be super high for the engine? And does that intake work on stock heads? If im not doing a cam and heads im just gonna do exhaust intake carb and distributor for now get some good sound and get rid of the CCC would it just be better to do the edlebrock 2020 kit ill attach a picture. And do i need a specific distributor ill attach pictures of what im looking at.

 

That "truck carb" is a much better calibrated carb for 350's in the power range you are looking for.......has nothing to do with cfm....the part number is 0-90670 Holley and I swear by these for street applications from 330 to 400+ Horsepower........
I have one on the shelf as a test carburetor......it is the versatile unit in Holley's catalog.....I can jet it up or down and stick it on just about anything.......no way that would happen with an Edelbrock without $200 of jets and needles and hours or time setting up for each application......I even put it on my own 406 to make a Car Show one weekend......it was down on power (too small) but it ran like EFI.......
The 0-90670 on the 2701 EPS is a great combo......

Edelbrock's are too difficult to tune, too sketchy on fuel pressure requirements and don't like anything under 13 inches of vacuum.......I can tune them, but no way would I intentionally install one.....the 66' in my Avatar had a 650 AVS on it and it ran perfect....after about 10 hours of tuning

Lars is a fan of the Truck Avenger as well......he sent me an E-Mail about a year ago of a 67' all original L-79 327 coupe that he had bolted a 670 Truck Avenger too and it ran perfect out of the box with three things done: Idle screws, float adjustment, and a yellow secondary spring in place of the factory one.......(comes with). Why would he put this on an all original L-79? Because an original L-79 carb is over $2000 restored and it is a dead ringer for the original carb, single feed, dual metering blocks, vacuum secondary....but has billet annular boosters so it actually runs better than stock, more responsive.

Jebby

 

Thanks @Jebbysan! Hopefully that covers the carb question.

I had great luck dialing in a ZZ4 takeofff distributor (genuine AC Delco OEM for a GM crate engine). They are still available new, 93440806. $450- is a bonkers price, though. I got mine on eBay for $100-, and dropped another $50- of parts into it. I really need to sell that, now that I am divesting of SBCs.

I'd also look at Davis Unified Ignition (D.U.I,) distributors, available here. They come dialed in.

Either way, follow @lars timing specs. Email him for his timing and HEI papers. His email is all over this Forum, so read some related threads and you'll find it.

https://performancedistributors.com/

 

Sweet thank you so much that is exactly the info im looking for thats what I’ll get. What about those distributors do they look good?

 

You do not need a tach drive distributor.....the Summit one is a Tach drive.....the Summit non-tach drive looks ok, has adjustable vacuum advance but no curve kit or instructions....this is important......
I am not a fan of Proform stuff.....

Look at DUI for a good unit.......

Jebby

 

alright i just looked around a bit is this one good?

 

If you order it direct from DUI....they will curve it for you......

Jebby