I am a new Vette owner and recent subscriber to this Forum so be gentle. About a year ago I rewarded myself with my dream car, a beautiful all original 1981 L81 Vette with only 34,000 miles on it. She is gorgeous ! Everything works, drives like brand new and turns alot of heads at every stop light. I need a few different view points here: I am torn between keeping it mostly stock for appreciation and value or getting into it a little making it more of a custom. I have added some creature comforts and upgrades as in: new custom Alarm w/ power locks,custom CD/Subwoofer Stereo system, Tinted Windows, Magna HI-Flow Cat and Flowmaster Mufflers. This car looks great, sounds great and drive greats, reallly not much to change overall. Question is: Are there any relatively easy mods that can be done to the Motor or ECM unit that would boost a few extra ponies ? A quick gear change maybe ? What about pulling the 350 and dropping a 427 or 454 are they direct swaps or would Trannies need to be swapped as well ? Maybe just massaging the 350 to maybe a 383 Stroker, just to kill the annoying little Mustangs Any comments would be welcome, she is my pride and joy and have always wanted a Vette, now I just want to show her off and enjoy the hell out of her !! Thanks for listening !

 

A 400 hp 383 stroker and a 2500 stall convertor will make that 81 a beast, even with the stock 287 ratio rear end. mine was seriously traction challenged after I did this

 

Most execllent, did this to my old 1969 Checy Stepside Truck, best motor I ever had. Any plans to change Gearing or leave as is with the stock ratios, seem low but great freeway cruising.

 

Your choice......you want to have some fun? You have already made some mod's......

Toss the freakin' computer first........(and if you toss the 'puter you must replace the distributor, and the carb).

Desmog.......

Cut out the cat and go true dual exhaust........

New intake manifold (Edelbrock performer).........

New MSD distributor........

New Carb...........

This wil get you about 30-50hp.

Now, you can go one of two ways from this point.

Left Path: Pull the motor, have it bored and honed, and have it rebuilt a 383 stroker, or, a 355 or 357 with some nice heads and cam!! 400 hp in these light cars is a blast!! Or get a crate, and set you original motor aside.

Right Path: Just add some new better flowing heads, intake manifold, and a new cam. Don't have to pull the motor for this one!! You can probably get up to over 300 hp from doing this, if your bottom end is in good shape.

Have fun.......an 81 will probably never be much of a collector, so mod it as you wish! But........save all your original parts, box them up, and maybe oneday you will have a reason to return her to original condition.

Good luck!!

 

Thanks Vetteman, which path did you go down, yours is looking pretty sharp from the pics. Kinda lovin it the way it is, but you know the urge what take long..

 

I'm basically keeping my outside original looking. (May have to change the hood with a very small profile scoop however.) Basically I have done all of the first part, and I'm waiting on my (2nd) crate motor to be shipped out Monday!! (That's another story). Have ordered a 355 crate with 385hp and 405 ft# of torque to liven it up!! Standard rear, tranny, and stall converter. New MSD ignition, and Edelbrock 750 cfrm carb. I also have a 600 cfm carb with less that 100 miles on it if your interested. But, I wouldn't put it on a stock motor.

I keeping all of the original parts, boxed up, including the motor block! One of my heads wasn't original, thus the added reason for the change.

Doing all the work myself, with some help. Believe it or not, all I new how to do to the car a year ago was change the oil.

Two books I highly recommend: Both by David Vizard (the wizard of small blocks). You can get these at most large bookstores..

"How to rebuild your Small Block Chevy". and "How to Build Max Performance Small Blocks on a Budget".

Both excellent, and easy to read and understand.

Have fun, jump in, and feel the power!!

I will again, very soon!!

 

Very cool, send pics of the new motor when you get her in, that thing will most suredly be a rocket. Hope you wont be idle for too long, Spring Fever has defintely sprung around here ! Thanks for the tips !

 

IMO the best mod for these cars is an overdrive. Just did this on my 75. Either a 2004r or 700r4 along with the higher stall converter. I've barely had a chance to run my 700r4 and I'm already in love with it. The deeper 1st gear and low cruising RPMs change the whole personality of the car. Do a search on these trannys and you'll find lots of info.

 

That's next for me!! This mod chit get's expensive, fast!! I also need to do some suspension work, and steering work. One step at a time!!

 

Well it doesn't have to be a mod. Just shove it into reverse at 55 mph and you can call it an upgraded repair.

 

Actually, I almost did that.......throttle stuck under the air cleaner after I put a new carb on!! Found out real quick that a new breather was required!!

Wasn't thinking clear enough to just turn the damn key off, so I threw it up into neutral real quick, motor readlined, backfired, and I heard "clank, clank, clank......" Thought oh chit, just grenaded the tranny. Ended up breaking a 1/2 shaft!!

 

I think I remember that episode. You sure seem to have more adventures with the Vette than the rest of us.

 

Yep, there was a thread on it!! lol........

Talk about bad luck. I think I should sell it and start over!

I've had it now for a year and 3 months, and the following has happened:

Had a flat and went to change it. Could not get the lock to open on the spare cover. Cut/Beat the lock off.......spare was dry rotted.

When I changed out the distrib. and carb, it started overheating and never ran the same.

When I was testing the new changes, throttle stuck, and broke 1/2 shaft.

Burnt up the brand new spark plug wires. (They were touching the exhaust manifold.)

Had to replace right rear bearing (that was a bugger).

Was going to a cruise-in, and overheated on the highway when the heater hose broke!!

Bought 750 cfm carb, it was to much. Bought 600 cfm carb, it was still to much for the weak motor.

Bought new crate to compensate for the weak motor, installed, and blew it up on a 1/2 mile drive.

Yea, you can say I have had a few adventures......

 

I went with a 454 and TH400!

 

ms vetteman,you need something a little tougher.what about jay leno's blastolene?
a tank undercarriage should hold up ok.

 

I was thinkin' about one of those good ole Plymouth Fury III's w/ the 383 in them. Man, that thing was a tank, that would fly. My dad had one, but older brother totalled it at 16 yrs. of age. Never got to drive it legally....lol.....

 

MsVetteMan:

you have a Private Message!

 

When I first started building my engine I sent Edelbrock an Email with my gas octane problems here and the high temps we have also. They came back with a package suggestion plus recommendations on pistons to use. I ordered all the parts they suggested from Summit including the 64cc heads and pistons, rods and rockers. I sometimes have a dieseling problem when the engine is hot as the fuel here is not regulated. With any stock 81 Corvette any thing you do improves performance. I am running the summit high output distributor and dynomax headers. I did have to install a plate under the carb due to high engine temps plus a fuel gauge and flow regulator due to the Holley high output fuel pump. In the future I may install a slightly bigger cam but not right now. I’m guessing about 350 HP as it is now. So from 190 to 350 it is a big improvement. You should be able to complete the engine for under $2,000, the heads being the biggest cost in this.

 

Great job Dean, you got a real winner! Thanks for the ideas.