cody

Ok, i've got an 86' Gt and im about to take the motor out and build it as a project this winter. I want to rebuild it, put all new gasket in it, heads, cam, intake (possibly carb switch). My goals for the car is somewheres between 260 - 300hp. The only prob is, i've heard that I cant put aftermarket heads on an 86' block.... So, what do I do? A buddy of my dads builds race stangs and he said that I could put some 289 heads on it, switch it carb, and have the heads worked a bit and have a mean lil street car. He has a built up 84' stang w/ a 289 that he built 13yrs ago and its still a mean running sonofagun... he said that I would also notice a major gain, since putting the smaller heads on there, therefore bumping up the compression. Any info on this topic would be greatly appreciated as always!
-Cody

bobby

cant put aftermarket heads on an 86, never heard any such thing[8D]

nemethjames1

you got so many heads to choose from, this guys bull****ing you, dont go with 289 heads if you got money, get afr's

callmecobra

yeah, there is an abundance of aftermarket heads for 5.0's. whoever told you that is an idiot.

mdvaldosta

Its not the block thats the concern when you go to an aftermarket set of heads, its the pistons in the 86 block. The pistons are flat-tops with no valve reliefs, so you will get PTV contact with virtually any cam of descent size or any head with oversized valves. Be very careful with your choice of aftermarket parts unless you plan to change the pistons or have them fly cut.

bobby

wow! i didnt know that md! thanks for the info! any other years have flat top with no valve reliefs?

mdvaldosta

Not to my knowledge, just the '86

roundman

rebuild it and bore it out so you can buy new pistons with good valve reliefs and then you can run the heads with valves as big as 2.08" if you get the right pistons to go with them. Just make sure that the combination of your cam, rocker arms, and valve sizes leave you with proper piston to valve clearances and you will be fine.
MD is right also, '86 is the only year where the Ford guys were braindead briefly!

bobby

LOL listen to roundma's advice!!!