I have a set of gt40 heads off an explorer that im finaly getting around to rebuilding and i was wondering were to get the valve stem seals and which ones to use. Ive looked on summit but my search came up empty could anyone point me in the right direction? The heads are for a 302 and i know i have to get the bolt holes opened up but does it make a difference on valve stem seals? Thanks Chuck

 

I just went to the RockAuto web site and looked up a 1996 Explorer with 302 V8. They have seals for your heads at various prices, all under $25 a set.
I have a set of those same heads off a 1993 Cobra Mustang and the heads came drilled with 1/2 inch head bolt holes from the factory.
Did you check yours or did you just assume they were 7/16? If they are 7/16 the 302 uses 7/16 head bolts so your shouldn't have to drill the holes bigger.
It's the 351 that uses 1/2 head bolts.
I know this as I plan on putting these heads on a 351!

 

They are going on a 351w but they came off a 302 sorry for not say that earlier. But RockAuto has them thank you very much for the quick response i can get moving on the rebuild after i get all the crud off the valves...

 

Are the stockers still the neoprene umbrella type valve seals?

If so, have the "Perfect Circle" type seals installed. The neoprene jobs crack and fall apart after not too long on the job.

 

The seals are positive seal types. Unbrella seals are not used anymore and i don't think they have been used for quite a few years. Emission/air pollution control may have something to do with that.

I found that many engines I took apart that had those type seals have heavy build up of carbon on the back side of the valves.

I cleaned my heads & valves, after disassembly, by running them through my blast cabinet. I used glass beads for media and blasted everything clean. I don't know what I would do without it. I removed the oil & grundge with oven cleaner first, then the carbon & rust from the heads& valves with the glass beads. The heads look almost new!

I only need to have the intake valves ground as they show some wear. The exhaust look nearly new! I will then lap all the valves to the valve seats in the heads.

 

I had to drill mine

 

Some years got drilled and some didn't. The GT40 heads were used on the Lighting PickUp int 1993 and the 1995 Mustang Cobra R and both used 351 engines so that year GT40 heads were more then likely drilled at the factory then the later GT40 heads used only on the Explorers and the 302 engine

I would buy a reamer to open up the bolt holes and not a 1/2 drill. Makes a round hole and easier to use. Also use a drill press and not a hand drill. You could go off center with a hand held drill.

 

Unfortunatly i dont have a blasting cabinet so i wouldnt be able to blast them the machine shop i was gunna take them too said they would clean and check them for 40 bucks a head but id rather do it my self if i could does anyone have any ideas or safe chemicals i can use i was thinkin just brake cleaner and a hard plastic brush for the valves but i dont want to ruin them

 

Oven cleaner and or paint remover. Can't hurt the metal and will remove most of the carbon and grudge.