Wierd Holley issue

[Jac Mac]

Wayne, you mention in post #7 that the old heads had a couple of worn guides- they wouldnt happen to have been from cyls 5&6 would they, if so the rings/bores on those cyls may be glazed, also check the stem seals those cyls & inlet rocker studs if they go thru to the port for sealant.
Leak down test 'might' help, but another way is to buy/borrow a 7mm or 10mm headed flexi lead TV camera that hooks up to your lap top, you should be able to get that down the #5 intake runner ( #6 might be a challenge with that intake manifold ), very handy tool to have these days, you can get these in thru a 14mm plug hole for a look inside the cyls as well ( just dont try it on a 'hot' motor), wish we had this stuff back in the 70's, but didnt have the $$ they were asking for borescopes back then.

[Dwight]

this link has good pictures of plugs and how to read them.

sparkplugreading

Dwight

[Wayne Maybury]

Gaz64, The plugs have just under 1,000 miles on them. They were installed with the new aluminum heads. The heads were complete so all new valves, springs, etc. The only parts added were new roller rocker arms. The carb is a Holley 4160, 600 cfm, elec choke, vac secondaries. I bought the Mustang 9 yeras ago and completely restored it from the ground up. I had the engine rebuilt at during the restoration since I had it out of the car at the time. The engine builder said the engine was in good condition but we changed the pistons, rings, cam, bearings, oil pump, etc, etc. I installed the new Holley when the engine was put back in the car.

Jay Mac, the #1 cyl had the worst valve guide and of course #1 is the easiest plug to pull on an old Mustang. The engine was using about 1 qt of oil per thousand miles so it wasn't really a lot. The engine did not take any oil (or anti-freeze) since the aluminum heads were installed this past spring.

Dwight, I am going to take a look, maybe I will learn something.

Thanks all.