I have a 76 K5 Blazer with a 5.7 V8. I put in a TPI from a 89-90 IROC many years ago and it has worked flawlessly since then. I am doing a body restoration on the K5, and decided to upgrade the 5.7. Weisco pistons, got the quench at about .038. CompRatio about 9.4:1. Decked the block .020 as well as the Vortec heads. I have a Scoggin Dickey TPI manifold for the Vortecs. Have moved up to 22lb injectors. Engine should be in the 300hp range

I am going to modify the K5 gas tank so the fuel pump is inside it. Any advice on this step would be appreciated.

Now that I have the hard fuel lines removed from the frame, I measured them. The supply is .375, and the return is .250. I am concerned that fuel lines, especially the return are not enough for 300hp.

Advice?

 

A lot of guys use the old feed for a return and run a new larger feed line.
the stock tpi 350 uses 22lb injs

 

That makes sense. When replacing the supply line, do most go with 7/16, or 1/2?

The old 19lb injectors came of a 305, but worked fine for my old truck motor. The new motor, which I described earlier also will have a mild RV roller cam. I'm hoping the 22lb will be enough. Will move lots more air.

Cheers.