hey i just wanted to ask/tell you guys of a little tpi swap qwirk ive noticed, i threw tpi on a crate motor specifically designed for it(lb9), and had no problems, but two of my buddies had terrible overheating problems. they used all the same parts as me, but one guys motor was a 87 (lo3) 305,
and the other used a gm goodwrench 350. both these motors ran at 220 to 250 degrees all the time. one guy finally called gm, the rep. said the problem was the motor needs the coolant crossover on the back of the manifold, but the tpi blocks this passage off. so my friend drilled and threaded a 1/2 inch npt into the back of the manifold to let coolant go from head to head. this solved all his problems. my other friend with the 350 is about to do the same. anyone else run into this?

 

Most TPI swap problems involving overheating is usually caused by using the wrong rotation water pump. I have no x-over in back and no overheating problems...