Gt 40-40 P heads need different headers . . .

 

What's so good about explorer heads? Are they suitable for a mild performance engine? Would tri-y headers work with them?

 

the intake and exhaust bolt patterns are the same as any other 289/302/351w.

the 1997 1/2 and newer explorers have the GT40P heads instead of the GT40's, which have a smaller exhaust valve, but a better exhaust port design, so they flow better..... but the spark plugs are angled so regular headers will hit the plugs.

whats so good about them? well, they flow better than the early 351w heads in their stock form and dont require hard seats and any extra machine work a 35 year old set of heads may need.

 

So you're saying my tri-ys would work with the GT-40 heads?

 

yes, yes i am

 

So what year of Explorer GT-40 heads do I want for my 289? What would be a good cam to go with them? Are the heads scew in studs or pushed in? What else do I need to know about them?

 

Arthur,

Good experience with him he knows his stuff and is not too expensive, 35+btw per hour. He started doing big healy's and then moved into to american's mainly stangs even though he doesn't drive one ( he has an old buick vert and is rebuilding a hudson hornet).

Paddy

 

The problem with the explorer heads is that they're going to be at least 10 years old.. are they in need of a valve job, seals etc? Factor that in and the price of a new set of headers and you might be better off with a set of aftermarket heads. The P headsuse pedestal mount rockers but I think it's crane that makes a rocker stud that screws into the rocker arm bolt hole. Dont run to big of a cam, it's only a 5/16 hole

Oh yeah, I doubt you can mill the heads enough to lose 10cc without having to mill the intake too.

19stang66, your headers would work with the GT40 heads, but probably not with the explorers GT40P's

 

yes the headers will work with the gt40's but not the gt40p's

i dont remember when the explorers started using the gt40 heads, but PRE 97.5 is what your looking for.

the pedistal style rockers are fine for mild cams, but the screw-in conversion kit is a nice route to go so you can run rollers.

right now summit has a sale on their in house grinds, and that 218/228 .471/.471 cam will work wonders for bottom/mid range power. stock springs *will* work but i suggest going a tad stiffer with this (or virtually any other larger than stock cam) 100 lbs of pressure at the seat would be a good place.

yes, knocking 10cc's off would be extreme and would require intake modification, but even dropping half that would be a big plus - and the better flow will CERTAINLY outweigh the small drop in compression.

 

well you can take about 7-8cc off safely but thats nothing a little piston mod cannot fix get domed pistons or sometihng to that effect cause you don't need a whole lot of space taken up