Hey. I have a 1980 corvette with a 350 and 4 speed manual transmission. I want to make some more power. My first question is what can i doin general to make it faster(from basic to advanced mods). My second question is what will i be able to do with $4,000?

 

If you are not worried about state smog inspection, you can remove the smog equipment. That's where I started on mine when I first bought it, then replace the carb/ intake, added headers and sidepipes. $4000 will get you a 383 stroker engine.

 

A set of headers and a 2 1/2" dual exhaust with performance mufflers, a re-curve of the distributor, and a good tune on the carb will get you a noticeable seat-of-the-pants improvement in power, and should cost well under 1000 bucks. You could probably even squeak in a used Edelbrock Performer 2101 intake manifold, you can find them on e-bay for, like, 50 bucks. After that, an overdrive transmission with a steeper first gear would make a noticeable improvement.

Scott

 

I would do a OD Trans first, and this will come with a Crossmember that allows a True Duel Exhaust, and that would be next. At this Point the 4k is probably used up. Then on to the list is a Heads-Cam-Intake or an Engine Swap. This all providing that the rest of the car is in good shape.

 

Stop playing around, add $1000 to your budget and drop in a crate ZZ4 and be done with it.
Here's mine:

 

ZZ4s are good, especially if you're fond of 87L-91 Corvette engines.

That said, they are good reliable engines and will get you back on the road fast, and with a warranty. You can make significantly more power for the same price but will have to deal with your engine builder's warranty and likely put some sweat equity into it.

 

Yeah, man, just go out in your backyard where the money tree is and pick another 1000 bucks off of it...

Scott

 

Hearders, 180 cc eliminators (afr) decent intqke and roller cam.. just my .02 cents.. skimp on the heads and youll replace them later.

 

Whatever you decide to do, one of the main mod's will involve setting up for dual exhaust. It's easy to say throw a crate motor in or swap out the cam, but in the end you will need the dual exhaust to make it work well. The 1980 4 speed has a bolt in crossmember, but the dual exhaust replacement (G-Force) is not setup for the stock shifter. The shifter bolts directly to the stock crossmember. You could cut the original crossmember and weld in a plate to allow the exhaust to run straight back on the driver's side. There are exhaust systems that will run both pipes under the passenger side, I believe that is Corvette Central. Would you run the original stock cast iron manifolds, direct fit McJack ramhorms, shorty headers or long tube headers?
Starting with an OD tranny would eliminate the problem of the shifter and make moving to the dual exhaust easier. Do you take long trips or cruise highway speed a lot? If not, there is nothing wrong with the 4 speed. Time to make a plan

 

i have a 1980 4 speed car. I started with a mild upgrade of heads and dist curve. Headders and dual exhaust. For some reason my cross member alows for dual exhaust...
A couple years back i wipped a lobe on a cam and decided to rebuild the motor. I stroked the 350 and man that made all of the difference. You could just start there. Stroke the motor. Have it done by a good shop in your area and then stuff it back in the car with a good set of summett headders and dual exhaust. You will love it and it will not be hard to drive. Dont go crazy with the cam selection. Talk to the builder a lot and tell him what you want to do. You race or dont race. I dont race i like to ride and from time to time light up the tires.... just the 15 year old in me! You can do all of this for 3 grand and still have money for beer for the guys that help you. By the way... have the 4 speed rebuilt when you have the motor out. You will be glad you did. It is fine on trips..

 

383 crate engine, headers and get rid of all computer and smog crap.

 

Any chance you could post a picture of that crossmember?

 

OK so maybe we are learning something new here. How many other 4 speed 1980 Cars are there out there with a Crossmember that allows for a Duel Exhaust? You 1981 guys can join in to...

 

There are loads of posts on here about true duals for 80-81 models. You can either modify your crossmember, it isn't hard, or you can buy one.

http://forums.corvetteforum.com/c3-t...o-hang-it.html

http://forums.corvetteforum.com/c3-t...cs-please.html

Type this "81 dual exhaust cross member" into your google IMAGES search and you will see dozens of them.

 

Buy one for an original 4 speed? Where?
I've done the searches. I called G-Force and their crossmember is for automatics or after-market manual transmissions. The original GM 4 speed shifter mounts to the crossmember.

As Gale Banks 80' said, "maybe we are learning something new here". I am hoping the OP posts a pic and it turns up a solution than is easier/better than cutting up the original crossmember.

 

I am probably misunderstanding your question. There is no difference between the manual and automatic crossmember in the 80, 81 and 82. They are all the same.

They bolt up as opposed to being welded. For the manual there is a bolt on bracket that holds the shifter. The automatic equipped cars have the holes and bolts already in them if you want to convert to manual. Piece of cake.

If I understand the original post, it states that for some reason his crossmember supports dual exhaust. This is probably correct as someone in the distant past might have converted it.

All the later C3 cars with cats have the X pipe and not true duals. It is my understanding that the earlier true dual cars have welded in cross members. The ones with the holes in them for the pipes to pass through.

I suppose you could get an earlier welded in cross member and modify it to fit your application and weld it in.

The crossmember in my 81 fits both the auto and Super T 10 I replaced it with perfectly.

I don't believe the factory ever intended the 80-82 cars to ever have true duals and thus didn't create a stock crossmember to do that.

 

This is a mystery that I guess only the OP can solve.

 

i do not have any pics of the under side of my car. I can take some but it will be a few days. the car is stored off site... It may have been retrofited. I am not the orginal owner.

 

You can get the greatest leap in performance for $1,000.

Have Lars rebuild/recurve your OEM HEI for performance. Same for the carburetor; set it up to compliment the recurve. This will give you a BIG seat-of-pants performance increase. stock advance and carb are for fuel efficiency. You may need an adjustable vacuum advance with the distributor rebuild as I recall mine was not adjustable (I had a tuner recurve my aftermarket Accel distributor that came with adjustable advance can).

Headers, true duals and turbo mufflers (I have Dynomax Super Turbos).

K&N filter in your stock dual snorkel air cleaner. With the stock ducting in good workng order, it will be fine. I disconnected and 'fixed' the intake doors on the air cleaner to keep them open at all times. I also removed all thermal switches from intake and rerouted the vacuum lines to compensate. I also connected distributor advance vacuum line to the correct carb port (per Lars' instructions).

You probably have the OEM aluminum intake manifold. No need to replace it. Edelbrock performer (2101 or 3701) are practically same as the OEM aluminum intake.

If you aren't happy with the improvement, For about $350-500 in parts, you can add a nice cam/lifters combo. If you have L82, the cam I would recommend doesn't have much more lift but you get it faster with shorter duration and tighter lobe separation Crane Energizer 272 H10 grind woke my L48 up. I found it a perfect compliment to the recurve/carb rebuild.

If still not enough, cylinder head swap for about $1,500

If you are really set on spending $4,000, then the next step would be to add gears. replace the rear 3.07 gears with either 3.31's or 3.54's. I also stepped up to a 700R4 conversion but after the gears, you will need to add to your budget if you want a 700R4.

You could probably add gears and NOS to the recurve/carb, headers/duals, cam/lifters and cylinder head swap and be at $4,000. And, in process, you will have a blast.

 

Buy a upper end kit from trickflow or similar.Add dual exhaust,new distributor,manifold and carb.If you change the rear end to 373 you will have a 13 sec 1/4 mile car.How do I know?Thats what I did!