Will boost help a motor with long tube runners pull past 4500 or will it just add to where it already is?

 

I believe it does. Willie shifts his LTR motor at 6000RPM.

 

At the track my times didn't improve shifting at 6000 comparied to when I shift at 5500, this is with SS runners and a good base but with the ****ty stock heads and cam.

 

I've ridden in a couple of 350 TPI cars and have experimented with shift points. Both were nearly stock (sorry, I don't have details). It seemed in both cars that there's a significant power loss over 4,500 rpms. In my stock 305 TPI, 5-speed convertible. I don't notice a loss until about 5,000 rpm. In my "slightly modified" 305 TPI coupe, it's a different story. Like Robert mentioned above, it pulls to 6,000 rpm and then some. I have taken it to 6,200 with no appreciable difference in power loss. In fact, when I get my engine back into the car, I plan on an even higher shift point with the addition of a different cam (range to 6,500 rpm) and AFRs Hydra-Rev kit.

 

In my 87' turbocharged GTA I did my shift's at 6800 rpms and there was a noticeable difference if shift's where made earlier. The engine surely was still making power beyond the 5500 rpms. I believe that the HSR intake with it's 58mm throttle body was the main reason for this. Heads where also ported with stock sized Manley valves and stronger double springs where also used, stock roller cam. All this was at 15psi of boost.