ok im currently tearing down a 84 351W H.O. im gonna build a STRONG street performance speed density truck. im not gonna swap to MAF. not gonna happen.

im between 2 cams. Comp Cam Magnum 270 Cam, and Comp Cam 35-349-8 cam. and i know the second one is pushing the limts of SD oh well.

my main question is if i get GT40 heads will i have to change the intake? im using my stock 92 EFI intake.

 

The Gt 40 heads will work fine with your intake , but if your building a performance truck you might want to switch to a different intake , the 5.8 intake isn't very good , if you could find a gt 40 or something similar would be better , conanski knows them well..he will chime in , i can't remember the name of the other intake.....Lew

 

ok i was getting conflicting opinions on it. some were saying i couldnt use GT40 heads with my stock intake.

 

The roller cam I'd now suggest for SD applications is the Crane 444211.. Crane Cams 444211 - Crane CompuCam Camshafts - Overview - SummitRacing.com

You can use any intake with those heads, the stock 5.8 intake is technically too small but the SD system is aleady going to have it's hands full compensating for the cam and heads, I think adding an intake will be pushing your luck. You will also discover that the port openings in the lower where they meet the heads are a fair bit smaller than the head port size, you can remove some material from the last inch or so of the ports to open them up a bit, but dont try to make the opening the same size as the head ports if that would mean removing a lot of material and leaving very little gasket surface. A step in a port like this is not necessarally a bad thing, it is sometimes included to help control reversion of the A/F mixture back up the intake tract and won't have a big impact on total airflow.

 

this is just a flat tappet cam block. its not a roller cam block. and i dont want to retrofit it.

 

OK.. use the Crane 444232 then.

 

will it produce a rough idle? cause i want it noticable.

 

With SD you can't run an aggressive cam, the cams that give you a rough idle don't give you alot of vacuum at idle & won't work with SD ....Lew

 

eh i understand that but any somewhat aggressive cam will give a rough idle. and ive seen plenty of SD systems running on pretty big cams. hell Trick Flow stage 1's in 5.0 SD mustangs all the time.

 

The crane cam idles perfectly smooth.. And with stock EFI and GT40P heads on a 351w it revved up strong past 5 k.

 

The Mustang SD system is not quite the same as the truck SD system, the car version has sequential injection while the truck doesn't.

 

well that blows...

 

If you want it to sound bad *** , its got to be bad *** , time to pony up...LOL

 

its gonna be a lil beefy. not a **** load but its gonna have some beef to it.

 

You will be impressed with that cam and heads on the motor I guarantee you, it will run much stronger than stock.