5.0l efi to HO

[bigpotato555]

hey guys have some question here...I bought an 89 grand marquis to put the 5.0l efi into my ranger...but I found out that it's a dam freaking nice car to drive..lol...I have found some gt40 head from a mustang...the guy has the heads, the upper and lower intake and the cam...I am wondering if all what needed to convert my 5.0l to HO...I guess the matching computer would not be a bad idear...anyway I would like to know everything to do and HO conversion...65 more hp would be a blast in the marquis..also are all the head use the same header?..i know gt40p from explorer use differents...if you have a good resource web site i would love to some reading!

 

[Gotta_gofast]

Actually, the 5.0L H.O. mustangs used the same E7 casting heads as the trucks and most other SBF of that era. If you indeed have the GT40 heads, there will be three distinct lines casted in the front of the cylinder head, each about one inch in length. The exhaust manifolds will work with either the E7's or GT40's design.

To finish your conversion to a cobra 5.0L (assuming the intake, cam, and GT40 heads) you will also need Crane 1.7:1 roller rockers. They came factory on the 5.0L Cobras. You can order them aftermarket through summitracing and jegs... The computers are different, too. You can either try to locate a Cobra computer ('93 5.0 cobra mustang) which will be quite hard to find, or simply have your computer tuned.

If your new parts are from any ol' 5.0 H.O. then all you need is the intake, cam, heads and the shorty headers (they suck). The computer will be easier to locate.

Now, if you have an AOD auto trans, then find a torque converter out of a 5.0L mustang as these will stall at 1900rpm vs. 1500-1600 for everything else. The AOD in mustangs also has a lighter weight governor which allows it to shift at 5000rpm WOT instead of 4500rpm for everything else.

 

[Beanmachine7000]

I thought I read somewhere that the H.O. engines have a completely different firing order... I could be wrong though...

 

[red85]

HO and 351W's use 13726548 firing order.

 

[Beanmachine7000]

HO and 351W's use 13726548 firing order.

So an H.O. motor has a different firing order than a non H.O.?

 

[puty72]

i thought the H.O. had forged pistons and the regular 5.0 efi did not?

 

[Mac]

The HO's were forged until around '93'. Other minor differences.
Dave