How much RPM increase will completely siamesed stock runners provide? Digging through old threads and seen some neat fab work. I have tig and aluminum mig welders at home and am thinking of doing this for a potential 383 stroker.

Is there anything to be done to a LTR design to get it to make peak power after 5000 rpm?

 

I remember when I went from stock tubes to the SLP partially siamesed runners back in the 90s when had TPI, I don't recall seeing a huge improvement.

 

For the work involved I would doubt it's that significant of an advantage. Just get a FIRST manifold and call it a day.

GD

 

I have read many of your posts about the first intake. What rpm are you peaking at? What cam?

 

Mine is a 276/288 Nitrous grind. Peak is 5110 on the iron Vortec heads but it pulls well beyond that. I'm still over 300 hp at the wheels at 6k.

I'm swapping to AFR 195's right now so I expect the peak to go up a few hundred more. The peak isn't as important with the FIRST though as it has a much broader power band than the stock TPI and keeps pulling well above 6k.

GD