81 Sport Coupe

I recently bought an 85 vette and really have enjoyed the experience of driving one it has 101,000mi on it, but after only 60mi unfortunately the motor started knocking, I pulled the motor and took it to a machine shop, after looking at it my machinist said he would bore it 20 over and put a 383 kit in it with forged pistons and AFR heads along with a cam, he's asking 5,500 to do this which Im not sure if this is a reasonable price? He said that I would have to find someone to tune it though, do you guys think it could run on a stock tune to get it to a dyno shop about 20mi away? or where can I get a good mail order chip? besides what I listed everything on the motor is stock including injectors so would I have to change any of this?

mtwoolford

anytime you get too far out of the box, a new tune may be necessary with any engine.

What do you want to do with the car? $5,500 is probably a reasonable price for what he's offering to build, but for that much money, I'd have to have a lot of faith in a shop before I wrote that check.

balance that against a readily available brand new GM crate engines with a guarantee/warranty: plain jane 350, $2,500; GM HT 383, 320 hp / 410ft/lbs (if I read the graph right) $5,607; ZZ383, 425hp / 449 ftlbs, $6,800.

the main thing is don't get carried away, don't get impulsive, don't buy more than you really need (especially with a street car, be honest there), and don't become mesmerized by the ambience of the speed and machine shop experience.;

and also, I assume your engine has a flat tappet camshaft; I'd really consider chucking the whole thing and going to a later one piece rear seal engine with the factory hydraulic roller for a variety of reasons, better seals gaskets, roller camshaft (no flat tappet lifter wear issues); of course the conversion requires a flexplate/flywheel change over, but that a small price to pay for all the added advantages.

good luck

Ronaldo

+1 on the roller block. You would need new injectors and another intake would probably also be a good idea.

I can't comment on the build price, but if your putting in a 383 with AFR heads, I would consider upgrading the ECM to a '165 and upgrade the MAF to one of Blowerworks (www.blowerworks.net) MAF solutions and let them tune it.

I'm in the proces of installing a 383 with AFR 195 heads and a FIRST intake on my '87.

Edit: I forgot, to make the tuning proces a bit easier, I would also install an Ostrich 2 emulator

whalepirot

Know your goals with the car prior to speaking with anyone!

Then, ONE recipe from ONE honest mechanic WITH experience. Marketing hype sells expensive stuff and may or not actually deliver, hence rule 1.

I love the butt kicking pull of the longer-stroke 383/406, etc. My block is a '70s old school with Comp roller. No one who has ridden along frowns, nay, "Holy S#^t" is more common.

Indeed, TUNE is the key to success and the best is custom done, on a dyno.

blackozvet

I bought a 4 bolt short 2 piece RMS rotating assembly for less than $2,000,
then put in a retro roller cam kit, for my '85.
If the $5,500 includes AFR heads, a retro roller cam/lifters, forged pistons, decent oil pump, and a good timing set (brand name roller) and its all bolted up and ready to put in, then its probably not a bad deal. Its surprising how quickly things add up. If you use your block then things like the sump etc will be re-usable.
Also ask about internal or external balance, you may have to factor in larger flexplate (168 tooth) a mini starter and a new harmonic balancer if you change from internal balance to external balance (which most 383 builds are)
If you have your engine apart get new injectors anyway (and thats a whole new conversation !)
You could drive it 20 miles on the stock tune, especially if you have the same size injectors in it, the 85's use 24 lbs, if you go up to 30 lb injectors for the 383 (which is usually recommended) you will need a retune. Fastchip do chips for the 85 computer.

DanielRicany

I can pretty much gaurantee that you will not find a dyno shop to tune that car unless you travel half way across the country, especially on the one year only ECM for 1985.

blackozvet

Thats right, waste of time trying to dyno an '870 computer.
Just get someone who knows how to burn a chip for them, put it in and drive the car.

Orr89rocz

Where you located?

Run a 86-89 165 ecm and maf for that combo or go speed density

5500 for a afr headed 383 is not a bad price

dizwiz24

Advice so far is good.

I have the later model lt1 style, so im not going to have as good as advice on the earlier style and tuning

Dont be one of the tards that spends thousands of dollars on the build, only to put the same crappy l98 style intake back on.

Ive seen a bunch of people here do that and end up making less power than a heads/cam lt1.

Im not sure what your intake choices are...


The other thing is i would recommend putting built forged components in there should you want to do boost or whatever in the future.

Again dont be one of the tards that will spend $600 on a radiator, but cant spend the money on the hard to get to internals.