Generation IV Internal Engine - LS7 heads on a LS3 Block?

I just got the new copy of GM High Tech Performance and they were swapping RHS LS7 heads on a LS3 block.

I didn't know that was possible.

The intake valve is smaller allowing it to fit an ls3 bore. RHS heads use the same valve sizes as the PRC small bore LS7 heads from TSP and a few guys have used trhem on their LS3 builds

a.k.a. "small bore heads" I have yet to see TSP market their LS7 SMALL BORE heads as such. If someone went solely by TSPs website, they don't offer their small bore LS7s anymore.

Well, lets put it this way, the definition of small bore here is 4.065 when referencing the PRC ls7 "small bore" head. TSP doesn't want people thinking of small bore and think of the 3.898 ls1 bore like the AFR small bore 225 heads so with the stock ls7 bore being 4.125 the 4.065 bore of an ls3 is a small bore which the PRC 265 ls7 head fits.

a.k.a. "small bore heads" I have yet to see TSP market their LS7 SMALL BORE heads as such. If someone went solely by TSPs website, they don't offer their small bore LS7s anymore.

Be patient, they will be in stock soon. Have you talked with TSP to see if they have them? They may have a few pair.:secret:

i just ordered ls7 small bore heads from TSP