LT1-LT4 Modifications 1993-97 Gen II Small Block V8

383 build, questions

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Old 04-22-2014, 08:01 AM
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Default 383 build, questions

So im looking to either build a block i have or buy a short block already assembled. Just looking for opinions on both routes. Checked out some rotating assemblies and found a SCAT package all forged for around 1900-2000.

Honestly i want to stay away from eagle and step up a little bit in quality. Now i dont know if i should buy a kit or just piece everything together? i have some AFR 180 heads. Figured i could send them to lloyd and mate it with a little bigger cam than im already running. Are my heads big enough? Id like 425-450rwhp if thats at all possible. Possible 100-200shot on top of that at some point in its life.

Just looking for a little help building an LT. I can even shop for used parts. Rather just go the new route though. Pretty much just need a short block and i have all the other supporting mods.

hopefully stay under 4k for a short block assembled and id think probably under 3k for buying all the parts and having it assembled. If i sound off let me know.
Old 04-22-2014, 06:05 PM
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If I was in your shoes, I'd find the shop you want to do the machine work and tell them what you want and see what they recommend. The machine work just for the block can cost around $2000 if you have everything done including splayed main caps and assembly and crank/rods/pistons can easily cost $2500 and you're not there yet. If you stay away from the chinese stuff altogether, it can cost a lot more to go with forged parts, but you can go with Compstar which is not 100% American Callies, but very good quality forged parts and stay within your budget or buy a good forged crank and the better Eagle rods and then get some good pistons. Your heads are a little on the small side and it would cost a bunch either for porting or replacing them with bigger port heads. It is easy to spend $5k on a forged and studded 4 bolt shortblock. You need a good oil system, intake, heads, cam, valve train, gaskets, bearings. You want 450 at the wheels NA and +200 shot so that is like 750 hp your engine has to make unless I misunderstood - that is a stout amount of power... There aren't too many places you can skimp and have that stay together very long. As to your question about kits, there's no real benefit there, best just to get the parts you need and build it right. You can buy a wine making kit for beginners and the wine you make will get ya drunk, but you're not going to win any prizes with it. One thing you could do is look at the guys on this forum's engine builds and model yours after someone you consider to be successful and reaching the goals you are looking for. They might even send you a copy of their build sheet so you can clone it.

One other option is to look in the for sale section and buy someone elses engine and save 50%. I've seen some good ones in there from time to time - people gettin out of LT1s.
Old 04-22-2014, 09:00 PM
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^What he said, it adds up QUICK if you buy the parts piece by piece and have a shop do all the necessary work. I bought my 383 forged shortblock from a guy on here who had it built but decided to go LS, those stock LS3 heads will put any ported aftermarket LT1 heads to shame flow wise, so definitely do some cost/benefit research on the subject depending on your ultimate goals as many have found and end up abandoning the LT1 platform and selling it off cheap. Personally, I'd just go LS rather than build an LT1 from scratch, I just kept it because it was cheaper, easier, and I don't have huge HP goals.
Old 04-22-2014, 10:14 PM
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Right on. Well I'm happy without spray honestly. If my head are not worth 383 I can just run a 355 and stay with 2 bolt mains? 400 to the wheels is fine. I was basically seeing if my heads would even want 383 or not. I have a block in my garage bored .030 and machined for a 3.75" crank already. Just looking at routes to go. I'm not trying to break any records. Just figured while I had it out go 383. But for the extra 50 HP for heads + new cam just does not sound cost effective.

Ive been looking around for a used lt1 assembled already just to save cause I know people go ls. Just haven't seen much lately. Don't really want to go ls in my 95 kind of saving my ls project for my 3rd gen
Old 04-22-2014, 10:24 PM
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I kept the LT1 because I didn't want to be one of THOSE guys. There's too much character with these cars and I really wanted something unique.

The LS is a fantastic platform and is better in almost every way, but if I see another 6.0 in a LT1 car I'm going to beat the owner with a driveshaft.
Old 04-22-2014, 10:25 PM
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425rwhp is on the low end of what you're looking for but it can definitely be done with some AI parts and a stock shortblock.
Old 04-23-2014, 01:23 AM
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Stock heads ported or my afrs ported be a better head?
Old 04-23-2014, 12:08 PM
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Yyou could probably get away with a 2 bolt main. No one can really say for sure when it's needed. Just keep your rpms modest enough and get a good tune.
Old 04-23-2014, 01:00 PM
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Those AFR heads will probably just get you there with a big cam and M6. They flow less on the intake side than ported stock castings but they make up for it on the exhaust. Then again, it's hard to say because flow numbers aren't everything. 180cc is pretty small so the velocity will be higher = more torque at lower rpm. It will be a whole other level if you get them ported.

I doubt 2 bolt mains will be a problem if your RPMs aren't crazy.
Old 04-23-2014, 01:14 PM
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2 bolt mains are good for any 350/355 within the factory PCM limit (~7100 rpm).
You'll get cap walk spinning a stroker to 7000 with 2 bolt mains.
Old 04-23-2014, 01:34 PM
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Your goals are very modest. If you want to save money, build a 355 reusing stock crank, port your AFRs, and have a decent sized cam spec'd for you.

The car will make over 425rwhp and save you a lot of money and unnecessary parts over a 383.
Old 04-23-2014, 06:51 PM
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Will probably go the 355,route then. Just need to find a local builder.

What rods and pistons? I've got about all the other supporting mods I just need the shortblock
Old 04-23-2014, 07:05 PM
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Stock rods resized with new bolts. I'd go with a lighter forged 4032 flat top for a moderate amount of spray. Don't be afraid of higher compression.
Old 04-23-2014, 07:14 PM
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Ohio crank sells a set of i-beams for around $180 iirc. Then just source some pistons.
Old 04-23-2014, 10:16 PM
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Stock rods? I don't have to go budget budget. I know stock cranks are great. Are the rods not worth upgrading?
Old 04-23-2014, 10:51 PM
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The powdered metal rods will live with stock stroke, 7k RPM PCM limit, pistons that aren't really heavy, and normal amounts of cylinder pressure. There are a few guys floating around with stock rods in their boosted motors without issue. I think you'd be fine.

The price of aftermarket rods isn't that much more. I'd shoot for something made from 4340 forged steel with 7/16" ARP bolts. The Scat I beams come to mind.
Old 04-23-2014, 11:43 PM
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Originally Posted by Camaro350Z28
Stock rods? I don't have to go budget budget. I know stock cranks are great. Are the rods not worth upgrading?
for a N/A 355 the stock rods are fine. get them re-sized and fitted with ARP fasteners.

Get good pistons, Mahle
Old 04-24-2014, 10:44 AM
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Read this:
http://www.hotrod.com/techarticles/h...nnecting_rods/

Rebuilding stock rods is old school and more money and trouble than it's worth with how cheap aftermarket forged rods have become IMHO! Most come with ARP bolts already, you very well might spend MORE reconditioning weaker factory rods by the time you buy the ARP bolts too....
Old 04-24-2014, 11:02 AM
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There are more factors than just the cost of new rods versus resizing when deciding to resize or buy new.
1. On the new budget rods you're using for comparison, do you think the big ends are round, or more specifically how long they will stay round after a few heat cycles? If you think you're safe, guess again. I trust a heat-cycled re-machined GM PM rod more than a budget aftermarket. Not just my opinion, ask somebody in a performance machine shop.
Bottom line: Buy QUALITY aftermarket, not cheap, or.....resize your stock rods.
2. Are you re-using the stock pistons? If so, you can avoid the balancing cost probably required with new budget rods. I know this isn't relevant to the OP, since I think he's going 355, but just for the benefit of anybody else who may go this route.
Old 04-24-2014, 11:42 AM
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If your local machine shop isn't top notch then chances are they're going to damage a piston or two when pressing the pins off.

I'd rather go the extra mile and resize cheap 4340 rods w/7/16 ARP hardware after stretching the bolts rather than reconditioning stock PM ones. Those Scat rods stand up to some heavy ****.


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