jbull

First time posting. Here's what I've got. 1979 Mustang coupe running an early 70's .30 over 302 with older Dart iron heads with 2.02 and 1.6 valves. Forged flat top pistons. I believe with the block decked and heads milled I'm around 10.5:1 compression. I normally run 108 race gas sometimes mixed with some premium pump gas. Chet Herbert solid roller cam, 292-580 advertised duration and lift. Chet Herbert roller rockers. Victor Jr. single plan intake with a Mallory Unilite distributor and Promaster coil along with Taylor Spiro Pro plug wires. Carb is a 750 Holley with mechanical secondaries. I'm running a TCI automatic with a small stall convertor and an 8.8 rear with 4:56 gears. I have a couple things I need suggestions on. First, what spark plug should I be running with this setup? What part number/brand? I think it currently has a set of Champion plugs in it. Also, what total timing should I run? I have the vacuum advance capped off on the distributor so I need a total timing setting to try. 36 degrees total advance sound right? My problem is a misfire when the car is under load.. like when I nail it from a slow roll or dead stop. It still runs pretty strong but definitely misses a little. As my speed picks up and the load decreases, the misfire will lessen and then stop and the car runs well. I've tried different carb jetting and even a different carb but it made no difference. If I'm running along at 30-40 and kick it, the car doesn't miss at all. It will miss if I shift down and really bring the revs up, but just a little. Seems worse when the car is coming up from a slow speed or dead stop. Any suggestions, advice or tips would be greatly appreciated. Thanks in advance.
Jeff

TwotoneVert

Sound like you have a pretty good setup. Have you checked the coil and distributor cap. Make sure the rotor is not burnt and you have no cracks. How are the plug wires? Nothing burnt or grounding out possibly? What about the fuel pump, although I cant tell you what type of pressure you should have. Welcome to the board, and post up some pics!

2 kwik

well plug the vaccum back up to the dist. what dist is it?
as far as plug..autolite or champion are fine as for plug number couldn't tell you as I would need to "read" plugs

jbull

I have replaced the cap, wire and Promaster coil too. Any other thoughts?

hellas85stang

302 in a 70sstand id say 36 degrees is ok ..but you have to adj that timing if u have a high po cam////try at idle 0 degrees and 36 totle..then go to 5 degrees adv at idle and 42 totle and go from theremay need to retard ya timing a lil at idle..but id say start at 0 at ide and 32 totle and go from there///do you have a better fuel pump withthose heads and cam u need one...i put a gas pressure gauge on my fuel line by carb and is gr8..u can check pressure any time.. try gettin a patronix2 ignition for ur stock distributprthere a goo upgadein electron ignition over point and the stock eec in newer fords...i have one layin around and i had a msd hooked up..it was gr8...controls the dwell ans every thing at high rpms..