found a 383 longblock for sale, that i'm looking to buy possibly. just have a few questions.

heres the original ad below.



[BLOCK IS BORED .030 OVER, CLEARANCED ,NEW CAM BEARINGS , DECKED .010 NEW BRASS FREEZE PLUGS ,LINE BORED ,


HEADS,ALUMINUM 52CC CHAMBERED ,NEW GUIDES, SPRINGS , 7 DEGREE KEEPERS , STEM SEALS , SURFACED , COMP VALVE JOB ,

CRANK; EAGLE 400 COMP CRANK, EAGLE RODS CLEARANCED ,

FEDERAL MOUGAL FLAT TOP PISTONS WITH VALVE RELIEF, KINGSTON RINGS ,12.5;1 COMPRESSION FLOATING PISTONS WITH SCREW IN LOCKS ,

CLEVETTE MAIN AND ROD BRGS,

SPEED PRO HARMONIC BALANCER , 400 FLEX PLATE , THE ROTATING ASSEMBLY HAS BEEN BALANCED TO .004

CAM SPECS;INTAKE 0.513 LIFT. 283 DURATION EXHAUST .498 LIFT .303 DURATION 107 LOBE SEPERATION THIS CAM IS A ROLLER CAM LIFTERS ARE INSTALLED IT IS SET UP TO RUN A DISTRIBUTOR JUST NEEDS TIMING SET INTAKE OIL PAN VALVE COVERS I HAVE THE OLD PARTS ALSO IF YOU WANT THEM ANY QUESTIONS FEEL FREE TO ASK AS IM SURE I FORGOT SOME THING]

is 12.5:1 too much for pump gas?

I am planing on changing the cam and heads, what heads would work well and lower the comp ratio?

are the federal mogule pistons ok?

 

Price?

 

$800

 

$800? Is that a typo?

The ad doesn't sound like an LT1 either.

 

Sounds like a 70's lt1 if anything. 4" crank? Lol sounds tight for a regular ltx

 

Federal mogul pistons are tough. Hyper eutectic are extremely strong but if a lean condition or detonation occur they usually take the whole motor with them. I have a stock bottom end topped with federal mogul speed pro pistons and they have seen a 150 shot over 50 times and have put me in the 11's repeatedly and once in the 10's. Just tore the top end down yesterday and they still look brand new.

 

An SBC 400 crank is a 3.75" stroke, not 4.00".

 

My bad was assuming they had a 4" crank. The pro stock motor I was looking at yesterday had a 4" crank,30 over pistons, which made it a 408ci

 

how much would stock 58cc chambered heads lower the compresion??

I would go with LE1 or LE2 heads and a LE cam

he said it was balenced with a flex plate, my car is a 6spd. would that matter?

 

Compression Ratio Calculator

This should help

 

said it was from a 1995 corvette, was going to run a carb

 

If the flexplate balance was played with then yes it would matter. If it was a stock counterweight then that would be easy enough to deal with. Most guys just go neutral when building an engine.

Is it an LT1?
Honestly the specs make me think it was done cheap and ignorant. IMO you should settle down stop chasing "cheap" engines that are wrong. The stock shortblock is better than cheap shortblocks. You can easily add a couple hundred HP to an LT1 before you need to even consider looking at the rotating assembly.

 

Aren't the 400 SBC cranks 2-piece seal? That would require an adapter for an LT1 block. What about the journals - diameter and width?

 

mou5e, you are chasing deals that are not deals. You're only going to screw yourself in the end. Sit back and read up on this forum. There are days of info on building blocks, buying blocks, etc. Learn, ask, learn again, then act.

-Dustin-

 

Why would you run a carb? If looking to run a carb why bother with an LT1?

The LT1 OBD1 pcm is probably the cheapest and easiest pcm to play with and it is easily fitted to a 96-7 car. The 96-7 pcm is easily reprogramable too but a bit more expensive for the software.

Honestly though if you are going to chase down "deals" on all the wrong engines and then slap a carb on it I don't think anyone here can be of much help.

If you want a carb then the only thing starting with an LT1 accomplishes is severely limiting your intake choices or making you spend a lot on converting an intake which is a bit backwards, especially when you are looking at mild "budget" performance parts.