I have done a search on the whole 15/8 vs. 13/4 debate,but most
of the cars were either 305`s or TPI.I know from past experience
that 15/8 shorties work great on mild 302`s and all the LT1 guys
are running 13/4`s.Everyone says the larger tubes hurt bottom
end.Is this true for us carbed guys too?

You loose a bit bottom end, you gain a bit top end ..

Depends on how the engine is build.

Ppl put 1 5/8 on 350's and 406's ..

Good for torque .. tho If you fell you have enough of that ..

get the bigger ones .. it'll free up some power un top.

I gained a noticable increase in higher RPM HP by switching from Edelbrocks newer TES headers to the SLP 1 3/4" with no noticable torque decrease.

The 1 5/8" vs. 1 3/4" debate belongs more to the full length header crowd.