are all Lt1 blocks the same???? i belive JUST the timing chain cover is diffrent on the 96-97 due to the OBDII system.

 

I believe the timing chain cover is different on the 95-97 cars due to the vented optispark, but I could be wrong.

To my knowledge, all LT1 blocks are basically the same. LT4 blcoks have 4-bolt mains instead of the 2-bolt mains that the LT1 has. Then again, my knowledge is tiny compared to some of the guys on this forum.

 

lt1 blocks will all basically the same, depending on how detailed u get, the only major differences, are like enisguy said, the 95's and up have the vented opti, and the different timing chain

brent

 

Corvette LT1 blocks have 4-bolt mains as well. Got one for the motor buildup on my '94.

 

Don't buy a 4blt stock main, buy a 2blt and have it splayed to a 4blt, it's WAYYYYYYY stronger than a factory 4 bolt, cuz the outter 2 are drilled at an angle, and more meat of the block is used to anchor the main caps, the maincaps I have seen on the REAR MAIN SEAL cap has a lil difference in the machined groove on a 97 vs a 93

 

while that is true a four bolt main block is plenty strong for the vast majority of street cars out there. want even more security use main studs instead of bolts. balance everything well use good parts and itll spin

 

I'm using a factory 4bolt main block with studs and caps No Problems.

 

2 bolt getting splayed billet caps...

 

also try Pinning the mains like old school ponchos are....prevents the cap from walking.We Do it on a lot of our high horsepower race motors at my shop..

 

There have been a few cases of 4 bolts being found in F-cars due to shortage of blocks at a particular factory that The Vette plant had shipped some to keep the stock rolling. But the 2 bolt LT1 is quite strong compared to older blocks due to more nickel content in the mix. As said by Snow Dog, the use of studs is highly recommended for hp levels above 450. The 93/4 f cars and vettes had no vent on the o/s ut the 94 Impala did. the Major differences are the timing covers and cam profiles but nothing significant other than the cyl heads...Impala had iron (initial design for the now "Vortech Head") vette and f cars had aluminum. All had pm rods, hypereutectic pistons and nodular iron cranks.