Dynoed my '77 on the weekend. I changed the diff, trans and engine oils and indexed the spark plugs as best I could (at least they were all pointing up!). The previous dyno run last year was done after I installed the stock heads with 2.02/1.6 valves, valve angle work, port matched Performer intake, XE256 cam, new lifter, double row timing chain, recurved dist and 9mm spiral leads. It improved the performance but not what I expected. I had already removed the cat converter and installed a twin exhaust (same mufflers). It ran 157.4 RWHP. :(:( I was a little disappointed with that although the car had some go!
Since then all I have done is install a new exhaust (headers, H pipe and mufflers), removed the choke & tweaked the carb (QJet). (I changed from 73/42 jet/rod combo to a 75/46).
This time it dynoed at 226.1 RWHP. :bold:bold:bold A gain of 68 HP at the wheels! :D:D
The best thing was the shop owner stuck his head in the car after the 1st pull and asked if I had a 383. ;laugh After the run he said “whatever you’re doing, you’re doing it right.” – I love that sort of comment! :D:D
Considering it won’t spin the tyres off the line, I think a new torque converter (or TH700) is on the cards.
Judging by this, either the stock manifolds a total crap or my mufflers were a bin job (one was rattling), or both.
I’m pretty happy with the results, so now I can stop spending money on engine bits and concentrate on getting power to the ground. Just when the missus' thought it was over! :P
