I bought an 89 F-150 4x4 that has a crack 5.8. I am going to swap it with a 5.0 that I already have out of another truck. I am wondering if it would be a good idea to put the 5.8 heads on the 5.0.

 

I think the 5.8 heads might have different bolts sizes and holes but Ford might have changed that by then. The old 5.8 had like 1/2 bolts and the 302 had 7/16, i think.

 

Other then bolt sizes would there be any performance increase?

 

Over the years the 5.8 heads were basically the same as the 5.0, especially in the 80's and 90's other than the different head bolt holes/bolts required they are the same, for the most part there are differences, what is stamped on the bottom of the head under the intake ports? It should say E***? Best you could hope for on a 80 block would be E7TE they have 64cc chambers and also came out on the 5.0 HO mustangs/truck motors. There are E5TE heads they are the same except they have 69cc chambers and a larger thermactor bump but the basic ports are identical. You need washers or stepped studs/bolts to intstall the 351 on 302 heads like fordeverpower mentioned. Good luck

 

Thanks for the help.