i was having problems with my '85 mustang GT pinging, and pressurizing the coolant. i tried to chase down the issue, but ended up sending it to a shop near me. they discovered the head gaskets were leaking, causing cross-combustion between chambers, the pinging i was hearing, and pressurizing the coolant. the car was also down on power--low 200's rwhp.
http://www.columbusracing.com/forums/showthread.php?t=64073
got the car back today, after the shop had it for a while. they did all the diagnostics (compression check, etc.) to diagnose the issue, did the head gaskets (heads got decked to assure flatness, valve seals, valve job), dyno tuned the car, and cleaned and tuned the carb. car laid down 275 rwhp--pretty pleased with that. he couldn't get a torque number for some reason--dyno was having difficulty picking up/sensing the rpms on my car (?), so i told him not to bother.
car has a stock '85 shortblock, explorer GT40 heads, e303 cam, edelbrock performer intake, holley 585 carb, roller rockers, shorty headers, stock midpipe, SLP loudmouth---pretty good for around 315 hp at the crank, or 90hp over advertised factory hp
http://img524.imageshack.us/img524/2971/imgl.jpg