running out of breath in the 1/4 mile

Exactly correct.... no way it will load it properly to simulate a 1/4 mile drag run. And it won't be safe for you buddy.

That pump looks exactly like the Carter M6866. Rating is 25 GPH into 4-5 psi.... period. Don't believe what the Summit site says; follow the link that 318willrun provided if you don't want to believe it; it's right there in black and white. It cannot be counted on to do the 35-40 GPH rate needed for you engine. And running like this means you are hitting a lean condition at a bad time====> potential engine damage.

The line out of the pump look like 5/16".

I am glad AJ has not seen the fuel lines to our carb!

I would like to see your setup and parts list as well.
Hope it's not too much trouble, but it's cheaper to copy a proven method and get it right the first time.
Thanks guys!