i was wonderign if the motor im goign to be gettign rebuilt and building up a little bit has a 4 bolt main.

it came our of an 88 chevy truck it auto with a 700r4 tranny and is TBI 5.7 LO5

im goign to be buildign it to make about 400 hp and ill be happy with that it will not be carburtated thow. im takign the old intake and ignition off of my 305 and using that.
consisting of:

Carter AFB CARB
Whehin Stealth intake
Hei upgradde kit
Hooker competition headers

on top of that im goign to have 10.1 forged pistons and a very high lift cam and also im goign to get the heads ported.

another question of mine is would it be better to use the heads off the 83 lg4 305 in my car now or are the 88 350 LO5 heads better???

also i have a good amount of time to do this engine rigth cause the 305 in my car right now was rebuilt 30xxx ago and still has alot of life in it and i plan on gettign its life out of it.

 

It could be, but there's no way to tell until you pull off the oil pan and look.

I can tell you the LO5 heads aren't "better" than the LG4 heads. They're just different. They've got larger combustion chambers (64cc) than the LG4 heads (58cc) so they're not going to give as much compression. But using the LG4 heads may put you over the pump-gas-friendly compression ratio. The LO5 swirl port design limits flow in the upper RPM range, but gives more grunt off the line. The LO5 heads have larger intake valves (1.94") than the LG4 heads (1.84") so they're gonna make up for some of that flow loss caused by the extra metal in the intake runners.

It all boils down to what works out better for what you want.

 

Is it a 1500 or 2500 or 3500?

I've noticed that more 3/4 and 1 ton blocks had 4 bolt mains over the half tons.

But as AJ said, it comes down to ripping it apart to see for sure.

 

should only be if it is from an 8600gvw or higher truck.

 

it is a 2 wheel drive 1500 vin# 1GCDC14K0JE119732

 

If it came from a 1500, it should be a 2 bolt. A 4 bolt would be nice but not necessary for that power level.

 

It's been my experience that most all truck motors, even from half tons, are 4 bolt mains, but thats far from a guaruntee. The only way to be sure with GM, even if it was out of a grossly underpowered semi, is to drop the pan and look.