BlackBeast2

When shopping for a replacement shortblock, such as a built 383 or 396, is there anything specific about the LT1 shortblock itself versus a standard 350 based sbc ?

95AquaC4

Just that the vette LT1's are 4 bolt, and the Impala/F-body LT1's are 2 bolt mains.

smacko

Thats wierd but interesting...
a friend here in OZ used to have a 1970's 'Holden Monaro' with a 350 and it had 4 bolt mains...

Mind you; it also had a 2 speed 'powerglide' auto in it so I guess it needed it, considering it spat out the modulator valve on regular occasions!

95AquaC4

I am speaking about the "new" generation LT1's. The ones from the 70's I am not too familiar with.

ANTI VENOM

I can't tell you all the differences, but there are some. Obviously, it does not use a top fed distributor ((but could), so there are some modifications for the opti spark. That also requires a different timing cover. I believe the water pump has 6 bolts on the lt-1 as opposed to 4 on the earlier stuff. It also is designed for a reverse coolant water pump. Long story short- you can't just drop a pre-92 sbc block in its place.

95AquaC4

Great points...I was assuming he meant late model shortblocks. sorry.

FD2BLK

The LT1 and the Std. SBC are completly diferent blocks and not interchangeable. Allot of the internals are interchangable such as bearing but the blocks are not the same. One look at the front of the blocks with the timing cover off and you can see the difference. The LT1 was desinged for reverse flow so the water pump attachment point and cooling jackets are different. The LT1 is also set up for an Opti distributor and gear driven water pump so the front of an LT1 is also completly diferent. You also need to make sure the stroker kit is for a 1 pce. rear main seal or for an LT1

Ramrod92

:iagree:

mackeyred96

Good info, :thumbs:

BlackBeast2

Thanks for all the info guys. As always, you are awesome. should have considered the obvious things like the water pump and Opti before throwing the question out there. :banghead: But as usual a few good spirited corvette owners come through to the aid of another with some good info and a wake up call. :cheers:
Now I see why all the Vette magazines have ads for shortblock kits that are LT1 specific.

Dave C. '04 Z06

FYI:

You can run an older style 2-piece seal crank in the LT-1 block (or any 1-piece block for that matter) if you get a seal adapter kit. The kit is about $30.

However, if you do this you'll have to get a different flywheel (or flex plate for the auto guys).

I have one in my big block and it works well. No leaks as far as I can tell.

-Dave C.

Arisa

There was my lesson learned for the day !!!!! Thanks