need some help with my 2.6 running bad

[NvrDoneD50]

i got my truck put back together and got it running...it has a weber, pacesetter header, gutted cat and a flowmaster muffler...ive noticed it when im driving it for about 45min to an hour it sounds like its missing and it seems like it doesnt have any power...i can tell by the tone of the exhaust changing.... so i had a buddy tell me to start a process of elemination....i changed the plugs,wires,cap and rotor....still does the same thing after running for 45min-1hr. so i went to the dis next...changed it and it still does the same thing...so im thinking its either the coil...which is the stock coil that came on the truck...so i tried to order a new one but it does not come with the resistors on the btm sides like the stock one...so can anyone tell me what might be wrong with my motor and maby how to retrofit a newer style coil? ive seen it done before just cant find it...


thanks for any help..

[TotallyBalistic]

are you still running the stock manual fuel pump or did you change to an electric?

[NvrDoneD50]

still got the stock manual one on the side of the head.... but would it make the truck run and seem like its missing after everything gets to operating temp?