Alright so first off I have a 1990 7.5l efi swapped into a 1988 f250 I've had the truck running before but recently I went to do new gasket set and got new valve seats and heads machined since putting back together I can't get it to run right I was just outside and I had it running it was running w me feathering gas pedal and if I let it sit and idle it eventually bogs down and dies and then after that it doesn't want to run at all it'll cut on for a second and cut right back out I have the in tank fuel pump which was the one used for the original 5.0 engine and an inline pump wired to a switch I feel as if w one pump Im not getting enough gas or w both I'm getting too much but also w the SPOUT connector unplugged it will start or at least fire up, with the connector plugged in it will turn over but will not fire up. Any help very much appreciated been dealing with this for a few months now
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Did you check lifter preload ? The things you mention that were done to your heads can effect push rod length. Too much or too little preload will have bad effects on an engine.