88stang5.0GT

are the 8 spark plug heads a direct replacement for 4 spark plug heads on my 89? and about how hard are they to find?

ExtrmZ

The head you are looking for shouldn't really be that hard to find, i am thinking that it should just bolt on to your single-spark block... but i am not totally sure, they had thoose heads in rangers, and mustangs too.. 91+ in the mustangs and i am thinking about the same with the rangers

sleeper_inc

the 8 plug head will bolt right on, but then you have the issue of firing the other 4 plugs... Just put a 4 plug head back on.

4 plug head - 74? to 90
8 plug head - 91-93, 89-95 (ranger)

88stang5.0GT

i already have a 4 plug head but the 8 plug head gave the 2.3's 20 or 30 horsepower more so i thought if i could just bolt it on with no problem it would be a quick way to get a little more acceleration because i almost cant handle how slow it is right now

ExtrmZ

its actually the cam in the head, not really the dual spark..

88stang5.0GT

oh i read somewhere that when they added that head they ported it more than the other ones and i assumed thats why the 91+ had more horsepower than my 89

ExtrmZ

those heads run a roller sytle camshaft and followers, they one you have in your 89 is a flat tappet style followers, they are less effecient, but still work.. when ford started putting the rollers in their cars, they put out a little more hp..

924banger

Port your 4plug head and go grab the roller setup off the year models Sleeper listed. You'll come out with more hp than the 8pluggers and you won't have to go through the headache and money to fire the extra 4plugs.

ExtrmZ

that would be the way to go, i did that, but i stuck with an aftermarket flat tappet cam from comp cams..

88stang5.0GT

if i wanted to do roller everything what all would i need to change? just the cam and rockers?