LT-1 Engine reverse flow

I am going to assume that the cooling system is doing excatly what it says, reverse flow cooling. Anybody know why it was done what advantages or disadvantages there are.

Conventional SBC had water coming out of the radiator, through the block and then the heads.

The heads are the hottest part (combustion chambers), and the water was pretty warm before it got there.

With reverse flow, the water comes out of the radiator and goes to the heads before going to the block.

The combustion chambers were getting a much cooler hit of water, which meant they could raise compression, run a more aggressive cam, etc.

Thats great! thanks for the info, was wondering why they (GM) were doing that. How expert are you with the LT-1 and Vortec. I still havn't gotten a good lead on if the short blocks are interchangable for the 5.7 l engines.

I'm up on basic workings on the LT-1 (almost enough to be dangerous).

Vortec is essentially all in the heads. The intake/exhaust manifolds are not interchangable.

You have a couple basic designs to be concerned with.

The regular small block (with perimeter valve cover bolts) hadn't changed a lot since introduction in 1955 (yes, there were some refinements, but it's essentially the same). These have a 2-piece rear main seal.

In 1987, (late '86 up), GM went to a 1-piece rear main seal, and other changes (including center-bolt valve covers).

You can't interchange parts between the two variations without an adaptor or a crank swap.

The LT-1 (and LT-4) are kinda sketchy w/me. With specifics questions/issues I can do the research and let you know.

Ok, now I am getting somewhere. I hear all the time about changing the heads to the Vortec on your small block Chevy to increase performance, so one has to assume that all the small bock Chevy blocks can accept the Vortec head, right? The engines in question are all from the late 80's to mid 90's. I even have a 91 5.0 TBI from another police car,so the short blocks with the info you have given should work. Is there any problem with coolant and oil connections between the head and older blocks? I keep looking at this 5.0 in the 91 and swear it looks the same as the 99 engine, less the heads and stuff. Is the anyplace that can give me deffinite info, on the interchanability of the blocks. Mortec only give casting numbers, but no interchangeable info. Thanks again