RSvert716

I'm restoring my 89 convertible and I want some more power too I am on a budget. Im more in to imports so I don't know the best set ups for Chevys. My goal is 383 stroker making 383whp/383tq witch I hear is pretty easy to do. I'm going to buy a scat stroker kit for around 700$. I have a gen I 4 bolt main block. I just rebuilt my 700r4 to corvette specs. And this is just gunna be a street cruser maby once a year on 1/4 mike strip for fun. I'd like to get about the same mpg as well 15 miles to the gallon.

Now here is where the questions begin. I'm sorry for asking questions everyone probly asks but it's hard to find an answer for every question with the set up I want.

Can I go carb instead of tbi with out doing any wiring? Or should I stay tbi? And if so tuning options?

What's the best head cam set up for the cheapest price to get me where I want to be? Are there any heads I can get out of the junk yard with mild porting that will work?

LSD/posi. What is a good rear end for my Camaro I have drums rite now with an open dif. I'd like to go disk and get a good gear ratio for my set up.

My budget for all of this is $2-3,000 I'd like to be on the low end of that but I'm realistic and I know It could end up a lot more than that. I allready have an easy 2k Invested on exterior and interior I'd really like to get her done for $5,000.

Damon

Converting an EFI engine to carb is easy to do. There is a sticky article in the TBI forum (and elsewhere?) about how to do it. The only thing you lose is the ability of the computer to lock up the torque converter, which you can buy a stand-alone kit to do, if that's important to you.

The factory TBI system is unlikely to support close to 400HP. People have tried, though.

Forget junkyard heads. A set of Vortec heads will get the job done at that power level. Like a set of Scoggin Dickey Vortecs with upgraded springs for more lift capability. Since you're buying an intake anyway, a Vortec-style intake really doesn't cost any more than a standard bolt pattern intake.

Cam should be matched to the heads and the rest of the combo- especially the torque converter. If you're running a stock stall speed converter in your trans, you don't want a big cam or it will be a total pig out of the hole. Since you have a roller cam block, I'd recommend you stick with a factory-style roller cam. Maybe something like the very popular LT4 "HotCam".

Do you already have headers, 3" exhaust? The factory TBI exhaust is NEVER going to support that HP level. It's all got to go from the manifolds to the tailpipes.

It's hard to beat a good Eaton posi for toughness, although the stock 7.625" rear is a known weak link and will probably break before the posi ever will. I have a cheaper Auburn posi in the very similar 7.5" rear under my 78 Malibu. After years of abuse, the rear end is starting to make "death noises", but the posi still works like a champ.

Of all these expenses, I think you'll find the cylinder heads and the exhaust is where you will drop the most coin. The combination of the two will probably eat most of your $2000 budget. But if those are your power goals, they're both basically mandatory.

EDIT: I just noticed you're talking about HP AT THE WHEELS. I was talking about at the FLYWHEEL. Totally different animals. You would need to go a lot more aggressive with the motor than what I outlined above to hit those numbers through an automatic. You'd need about 450HP at the flywheel to hit about 380 at the rear wheels. 450HP is beyond what stock Vortec heads and mild cam is going to get you. Unless you're willing to put a nitrous kit on it. Then it'll come easy, IF you have enough fuel system to support it (the stock TBI in-tank pump is probably not enough to support it). If you're into imports, you shouldn't be too afraid of nitrous!

RSvert716

Yea I have a set of stainless steal short tube headers I'm gunna buy some tubing from speedway and run a true duel 2-1/4 cat less exaust. I priced it out like 350$ with mufflers. Sounds like some pretty sound advise though thanks. I seen on a truck 383 build that a holly 750 carb is what I should go with what do u recommend? Also any heads I get I'm gunna do some mild port work, and port matching. Right now I'm running the stock tc I think it's 16-1800 stall, I was gonna go with a 2500 stall no locking converter. I was considering also going with a 75 shot of nitrous cuz the carb systems are cheap. But I don't want to have problems with the trans or engine after spraying a few times. Also what cars in the junk yard can I grab a rear end off of that will have 3.72 gears with posi that will bolt rite up? And one more big question valve train? Some say go bigger than recommend on the heads what do you say?


Don't some trucks have 5.7 with vortec heads in the junk yard?

rusty vango

I would leave NOS alone .as you state that you have no interest in breaking parts. and if youre gonna drive it on the freeway ,you need OD." hawks third gen" has the 10 bolt posi with disc brakes you are looking for. but you also need a different proportioning valve to convert from drum to disc. as for valve train, if you intend to spin it tighter than 5000 RPM ,THEN you need better (read more expensive) valve train gear.

RSvert716

I thought the redline was a round 5500-6000 rpm stock If I was gunna spray it would only be once a year but I don't want even that to **** up my engine. So if it will with this mild build than that's out. My main question with the rear end is what junk yard Chevys have one I can rip out change the seals and hold up with also having disk breaks? So the general consensus is that I should get pre assembled vortec heads, then just do some mild port work?

rusty vango

our cars take a specific rear axle. so for a bolt in deal its 3rd or 4th gen only. that's firebirds and Camaros. I personally don't trust pre assembled heads. I would rather buy bare vortecs and port them and use the parts of my choosing.

Night rider327

iTrader: (13)

The ONLY OEM rear ends that will fit our cars is 1982-92 camaro/firebird.. The 1993-2002 camaro/firebird will also fit but is a tad wider and you must run 4th gen wheels (or wheels that's spec'ed for the 4th gens)

The vortec heads came on all 1996-2000 full sized chevy/gmc trucks, vans, suv's with the L31 5700 5.7L 350 cid engine.

Your budget and goals are not in order. You will be very hard pressed to build a 383 RWHP 383 for $2,000-$3,000.. 383 HP at crank, even 400 HP at crank can be done with your budget and Vortec heads, but pushing that another 40-60 HP is gonna take more head and more money. Like Pro filer, Brodix IK, AFR heads.

You do know about the clearance probs building a 383 right? A lot of people hear about 383 strokers and go that away before they learn about the issues.
The block's oil pan rail, and bottom of cylinder walls has to be ground out to make room for the longer stroke crank to fit with out hitting. If you are not careful while grinding you can break into a water jacket and ruin the whole block. Some can do this others can not and most pay a machine shop to do that work.

Also the rods/rod bolts can hit and depending on cam you go with you may need to grind on the rod bolt shoulders, or replace with stroker clearanced rods and even go with a small base circle camshaft.

Yes you can do a carb swap and not really have to mess with very much wiring at all. It's very simple to do the TBI to carb swap.

Being you said mostly a street car, I wouldn't recommend a 750 cfm carb.. More like a 670 vac. sec. holley

You have no need in going over 5500 RPM with a 383. The 383 has the longer stroke and makes gobs of low and mid range torque, plus the rod/stroke ratio is bad on even a 6.0" rod 383 and this loads the side of cylinder wall more.. Keep RPM down on a 383 unless you want to shell out very big money to build a high rpm, long rod 383.

For your useage I don't think 3.73 gears is the best way to go. Your 383 will again make massive low rpm torque, you already have a deep 1st gear transmission, adding a 3.73 rear gear will just blow the tires off and run you right past your torque band.

3.42 gear would be my recommendation

Tibo

iTrader: (15)

I have a 383 that was based on engines that made 500-550 horsepower at the crank which is slightly more than what you would need with an automatic. I have around 5K in the engine as a turn key but I have efi. If you want a quick Thirdgen without making crazy horsepower look into purchasing a 5.3 LS truck engine, change the cam and add a single turbo. Done. Guys are making 500 wheel horsepower without issue. And if you break it who cares! Go buy another for $200-500! That setup will be well within 2K. But it will require some times spent swapping some parts out.

Orr89RocZ

iTrader: (20)

Probably gonna need to turn atleast 5500-5800 to make 383 wheel power. I made 392 heat soaked at 6250

RSvert716

What trucks year and models have this engine? And how about a twin turbo setup with a blow threw carb? I'm thinking twin gt28's quick spool times and good for about 12psi and there cheap too. I could have a set up like that for around my price range. I just do not want to do an efi swap so no matter what I'm going carb. My other idea would be a 383 with a skat kit. Stock heads with a mild cam single turbo. Same way the only thing is from what I hear is the heads are the most important part with the sbc builds so can I make good numbers with stock iron heads and a turbo. Thanks for all the advice everyone.