: 351m backfiring through exhaust under a load


tacobuggy101
02-08-2008, 01:17 PM
Ok i traded around some of my broken junk for someone elses broken junk. I ended up with a 79 150 435/205 and 78 350 auto/divorced case lp44?/60. On a side note would ford have done this or am I a victom of p.o. 60 theivery? Back on point, I can't for the life of me figure out what up with the 351 in the 1/2 ton. The motor was "freshened up" by kid that really didn't need to be inside a motor he may have the timing gears a tooth off b/c of 35ish* of in. timing:eek: to get to run or the wrong harmonic balencer. But it does run and is actually pretty stout except for some heavy hest. under throttle and it "pops" through the exhaust under heavy throttle, light throttle, normal driving, stand still reving, etc. I've been through the carb twice, new plugs, wires, cap, the normal tune up stuff. All but # 6 and 8 plugs are burning real clean (maybe a little lean) . They don't appear to fouled but they are always a little wetter than the rest. I've searched and searched but no one problem seems to be close enough to mine to provide any help. Any body got an idea?

Anyway if your feeling froggy flame away but I've been hear along time i just don't post much:flipoff2:

Thanks, Jake

jopes
02-08-2008, 01:27 PM
F350 should be a 60 up front. someone probably picked up the f350 pulled the 60 and put in a 44hd.

as for the timing, ignore the marks on the balancer, they have been known to spin on there. bring #1 up on the compression stroke and mark the balancer with 0 when it is @ TDC. unless the timing marks are still correct.

If he has 35 degrees base timing something is totally fawked up in there.

GMCTruxrule
02-08-2008, 03:58 PM
Sounds like you need to reverify valve and ignition timing to start with.
if your having doubts about the balancer, swap it out.