5.0, H.o ?????
 

What does H.O. mean? Are all 5.0's H.O.'s? If not, how do you know if you have an H.O. ?


Thanks
Larry

H.O. means "High Output." Not all 5.0's were H.O., but all the ones in the mustangs were.

It's been a while but I think the intake cover plate has 302 HO stamped on it.

Like already mentioned, the 5.0L HO stands for 5 liter, high output. They're distinguished by factory headers from '86+, 5.0L HO intake cover plaque, and a few internal changes from the non high output engine.

The H.O. has roller cam and lifters. The H.O. has a different firing order than the non h.o. The h.o. firing order is same as the 351W firing order. The firing orders are as follows:
H.O. 302 and 351W: 1-3-7-2-6-5-4-8
std. 302 1-5-4-2-6-3-7-8

Thanks guys for the information.


Larry

Are 5.0 HO engines good engines?

(I have an '87 5.0 H.O. engine in my '66 Mustang.)

85 was first year w/stock roller lifter. I had an '84 5.0 HO.

The 5.0 HO first came out in the 1982 Mustangs. In 1985, they started using roller cams and "factory headers". In 1986 they stopped using carbs, and went to speed density SEFI. Also, from 1986 on, all 5.0's installed in passenger cars used the exact same block as the HO. While the HO's came with a roller cam, most of the others came with a flat cam, but could accept a roller cam. In 1988, the Mustangs sold in California switched from speed density to Mass Air. In 1989, all of the Mustangs had Mass Air. Also, the truck 5.0's all used the same block now too, meaning that even though they came with a flat cam, they would accept a roller cam. In 1993, they switched from forged pistons to hypereutectic (sp?) pistons.

All of the 5.0 HO's, as mentioned, used the 351W firing order.

:)

Take care,
~Chris

lol, I need to learn how to type faster. Didn't mean to duplicate that info.

:)

Take care,
~Chris