I've got a 86 TA with a built 350 but I'm having some trouble. I have what sounds like a consistent "chuff" whenever the engine is running, along with a random misfire. The noise gets louder under load and quieter when deccelerating, and the misfire goes away as soon as the rpms are higher than idle. I've tried replacing all of the exhaust gaskets multiple times with no success at fixing the problem. After doing some research I tried the whole 'exhaust sucking test' and it appears to have a burnt valve. I also tried to check the compression but with the headers I have on it I can't check many of the cylinders.

Does anyone have a better way of determining if I do in fact have a burnt valve, besides tearing the heads and/or headers off?

Also, I was just able to pick up a set of 354434 casting 305 heads for $40. I am considering rebuilding these and then swapping them with the 882s that are currently on the car. Plus, the valve stem seals are getting old (I get the nice puff of smoke on startup occasionally). Are the any problems I may run into doing this?

Oh, and this is a daily driver. So any work that I do has to be able to be completed in a weekend. Any help would be gladly appreciated.

 

Really hard to diagnose something like this over the web but that sound is synonymous with a bad valve. Try pulling the plug wires one at a atime while running to see what the change is in pitch?

Somehow gotta do a pressure/leakdown test that should tell all.

 

Did the compression test, the results were;

#1-135
#2-130
#3-145
#4-110
#5-145
#6-120
#7-140
#8-110.

Any other ideas?