Cascade Crew

[84transam383]

ok so i bought a 85 chevy k30 pickup,with a big block in it...had a small engine fire

ive been replacing all of the fire damage and am just about done,save for the wipers and rad shroud

anyways,im having a bit of a problem,i threw my demon 750 on the truck and a proform distributor both brand new,to get the truck running again.

heres what im experiencing,i was driving it today and finally went WOT,it ran great and pulled HARD until about 4800 rpms,when it backfired and sputttered a few times,so i let of the gas.

tried it again but kept my foot in it,it sputtered and backfired again,and when it got to 5200,it just stopped and kept pulling hard until it shifted into second which was around 5700 5800 rpms,did the same thing going from second to third

ive played with the timing,right now i have it set 34* total,and ive played with anywhere from 28* to 42*,and while the timing does change the way it runs and the power,the stumble backfire is always there,no matter what the timing.

total motor setup,as i was told when i bought it
comp xe 4x4 cam 224/230 .550.570 lift,has 1.7 rockers,2 inch headers,3.5 inch exhaust all the way into flowmaster 10 series race mufflers,edelbrock perf rpm intake,msd wires {which i just bought today} and a 6AL box,which as i bought it is chipped at 6k,im running NGK plugs which are new as well,thats about all i can think of...oh and the jetting in the demon is from factory,its a mighty demon 750

[chevymad]

Almost sounds like the fuel pumps not keeping up.. backfires and acts up till it catches back up then goes again.

[84transam383]

hmmm,i never thought of that....i was going through receipts from when i bought the truck,and found new fuel pump records,so i kidna ruled out a worn one,its a stock replacement,i might go ahead and pop for a electric since i wanted to redo the fuel system anyways,ill give it a try this weekend and post back up,thanks for the tip dude!