Well something really wierd and really cool happened to me today. I have been in the process of installing LTs and I decided to change out the oil pan gasket as well. So I am down there fighting with the K member and I finally get the oil pan out so I can see the crank, and what do I see.....

4 bolt mains????

To my understanding the LT1s in the F-bodies never came with 4 bolt mains, and I am the second owner of this car, and the first guy who owned the car didnt know crap about them, and he told me he never tore into the engine.

So that leads me to believe that my car came with 4 bolt mains stock??? is this possible, has anyone ever heard of this before??

Either way I am really happy, because I was going to put some 4 bolt mains in anyways.

 

The corvette lt1s came with 4 bolt mains so maybe the original engine blew and they put a lt1 from a vette in there? Either way thats a nice thing to find wish I had 4 bolt mains.

 

What year is your car and is it a vert? I heard a rumor once that some of the convertable cars that were made in 95ish got the 4 bolt main LT1s.

 

That's cool stuff if it's a 4 bolt. Is it all of them, or just the end 2.

 

I wouldnt be surprised to see some 96-97's with leftovers.

 

Its a 97 T-top WS6 trans am, it is supposedly the original engine.

Yea I am really excited, I was going to spend all that money on the 4 bolts mains, but already got them, its like winning the lottery and finding out a couple months later, hahaha.

Yea its like all SBCs with 4 bolt, it has the three center with 4 bolts

 

Cool stuff.

 

whats the deference between them, sorry for asking, but I'm new o this.

 

The mains hold the crank in the block. The outer 2 have 4 bolts, and the inner 3 have 2 bolts. All his have 4 bolts, so his is a 4 bolt main.

 

Suppose to be stronger. I used one. Got it from Saudi.

 

Nice find.... does the engine vin match the car????? AFAIK the ONLY LT1's that came with 4 bolt mains were vettes....

never heard of ANY convertibles coming with 4 bolt mains..... and i've researched the hell out of it...

Either way whoever said they wish they had 4 bolt mains you can get them if you want....pay a machine shop to convert your block to 4 bolt splayed mains.... like this...

 

Here are some pictures I just snapped with the digital camera

 

waste of time unless yopu plan to buid the rest of the motor though

engine dosnt have a vin on it

brook

 

Well I just was looking around the engine and it was the GM crapgasket on the oil pan so my car most likely had 4 bolt mains stock this is blowing my mind, every single person I had talked to and everything I had read says that only vette LT1s had 4 bolt mains, I guess I am lucky. Its karma randy, its a funny thing

 

Of course.... hell there wouldn't be much reason to have the motor stripped down to nothing so you CAN 4 bolt main it unless you plan to build the rest no????

It must have some type of serial # on it to identify it somewhere.... How else would cops know if you have a stolen motor in your car? (Seen it happen to a buddy of mine) Wasn't an LT1 but there has to be some identifying mark on it somewhere....

but back to the point that is very weird that you have a 4 bolt block.... in an f-body..... do some research on the VIN #.... Might just find out it was some test development mule for Chevy or sumthin.... They don't always keep the cars they used at the factory for testing/evaluation forever.... they end up on the road like every other f-body.... Research the VIN and consider yourself lucky...

 

My 1995 also has 4 bolt mains, but pretty sure its not the stock engine.

I believe if an engine was replaced under warranty you got the 4 bolt version also.

 

I don't know for sure if this applies to f-bodies, but on lt1 or lt4 corvettes, the last 8 digits of the vin are stamped on the deck surface of the block (the same surface the head bolts to) on the drivers side, above the oil filter location. On an f-body this is probably pretty far up under the firewall.

 

I recall the B4C (might be remembering the RPO wrong, but cop cars) came with 4-bolt mains... There was a thread on it last year.

I dont know if GM does it, but for example Mopar has done forever... My 440 has a vin stamped on the block along with a casting date, etc...

 

how much do machine shops charge to change it to 4 bolt mains?

 

Good Deal!!

I ordered a used LT1 from the local salvage yard and I was pleasantly surprised to find it was a 4 bolt main. Looking into it they were used in the vette, SS and surplus units were sold as OEM replacements from GM.

PS-Forgot to mention some of the surplus units made it into other models



PPS- I blew that one up to.