will any cam/crank work on the LT1 block? like if im lookin in summet all the components that will fit lets say a ...87 small block will fit a 1994 lt1 small block?...about to do a serius rebuild and dont no a whole lot about the lt1 block, also is their...ANY site with a complete bearing kit for bottom end? thats made to handle high HP...only ones ive seen have been stock replacements

 

The LT1 uses a 1-piece rear main seal. Gen I SBC's use a 2-pc. seal. Most any SBC crank designed for a 1-piece rear seal can be used on an LT1 block. The block can be modified to use a 2-pc. seal crank, but in general this wouldn't be logical. Of course, unless it's a crank specifically designed for an LT1 and stock pistons and rods are used it will need to be balanced, but that's true of most any crank you use so I am not even sure why I mentioned it. BTW: the bolt circle on the 2-piece rear seal crank flange is larger than for the 1-piece seal cranks. This is stronger and preferable for ultra-high HP applications and the 2-piece seal cranks are thus used in all high end SBC race motors. The adbvantage of the 1-piece seal is that it's less prone to leaks.

Just to be sure I'm being clear, certain gen I SBC's produced after '88 (if memory serves) also used a 2-piece rear main seal. So it's not just gen II's (LT1/LT4) that have the 1-piece rear main seal. A quote from the GMPP catalog: "A leak-resistant one-piece rear main bearing seal was introduced on production small-block V8 and V6/90ş Chevrolet engines in 1986. Crankshafts in these engines were also redesigned to accommodate the new one-piece seal design. This adapter kit allows you to install an early-style crankshaft designed for a two-piece seal in a block which is machined for a one-piece rear seal. This seal adapter can also be used when installing a heavy-duty crankshaft in a cast iron Bow Tie small-block or Bow Tie V6/90ş block machined for a one-piece seal.

Technical Notes: The crankshaft seal adapter kit includes a two-piece aluminum seal retainer and related hardware. It does not include a gasket and two-piece seal; use pre-1986 two-piece rear seal P/N 10121044, retainer gasket P/N 12555714, and dowel pin P/N 9441003. The large outside diameter of the seal adapter requires a 1986 or later oil pan and gasket set. See the Chevy Power manual for installation instructions. Hex bolt P/N 10051121 and washer are used to hold the two halves of the adapter together. Bolt P/N 10051123 is used to hold adapter to cylinder case."

As far as cams go, the cam snout needs to have the correct dowel pin and center hole for the Optispark in your '94. The cam installed in ’94 and earlier cars differs from the later cam. The early cam had a short dowel pin (0.320”) that locates the timing gear. A center hole with 16 splines drives the distributor (Optispark) via a short shaft. Cams on the ’95 and up have a long dowel (0.685”) that drives the distributor and locates the timing gear. The center hole lacks splines and serves only to seat the distributor pilot shaft. So a cam for a gen I SBC will not work.

Welcome to the wacky world of the LT1!

Rich Krause

 

i have a 350 4 bolt main with 1 pce rear main seal. External balanced shortblock, will this bolt up to my LT1 heads and intake?

are LS1 heads better than LT1's? (to port n polish) and what cam should i go with, if its still my everyday car but i want it in low-mid 11's?

w/o nos or blower< but i am goin to put a blower/nos cam in it bc i will eventualy have one or the other>

 

Sounds like you may have a "Gen 1" block. Does it have the front of the block cast for the OptiSpark and gear driven water pump? You can't put LT1/LT4 (Gen 2) heads on a Gen 1 block, unless you modify the coolant passages by closing off some of them and drilling a couple new ones.

You also can't put LS1 (Gen 3) heads on any block other than the Gen 3 (LS1/LS6, C5-R and iron truck versions). The LS1 heads are a totally different configuration (I-E-I-E-I-E-I-E) and head bolt pattern (4 bolts/cyl vs. 5) than the earlier Gen 1 and Gen 2 heads.

And you can't build a setup for "either/or" a blower or nitrous. You're going to want to use a CR in the range of 9.0-9.5:1 with a blower motor, while a nitrous motor is going to be at least stock LT1/LT4 compression or greater.

 

Fred, what about the farm truck heads? The ones that go E-I-E-I-O?

Sorry, it's late and I am being real silly.

 

alright...so to add yet another q into this... will and LT1 crank work in a standard SBC block... i have a 4 bolt 1 piece rear main seal block... i am buying a buddies PM rods and have thought about the crank as well... will it work in the non LT1 1 piece rear main block? i know it will balance better cause the rods and crank will be coming as a set

 

It should work. It will, of course, need to be balanced.

Rich Krause