The V8 Owners Forum -

I've been given a set of HRC2479 heads and i have a 3.5 P6 engine my friend wants to rebuild.......will they be useable or are they just for 4.0 engines and up and if they are good are the accessory holes the same as the earlier heads........

They will work fine so long as you use comp gaskets. I would say they are a step up on the old P6 heads but pretty much the same as any after that barring the smaller combustion chambers for the thicker gaskets. They do have larger ports (just) than the 3.9 heads but they don't come standard with wasted valve stems the net result of flow is the same. The accessory bolt holes aren't in the same place though as the early heads but thats nothing that cant be overcome pretty easy.

Is the car that you are rebuilding the engine for a P6?

These heads as a result of their design will flow better than the P6 heads, and as such changes will need to be made to the fuel metering else the engine will run lean.

One of the bolt holes at each end of the head is of a larger diameter than the same in the original P6 head.

Ron.

Hi

"One of the bolt holes at each end of the head is of a larger diameter than the same in the original P6 head."

How do you ovewrcome this? I take it the P6 cylinder head bolts are too small then to fit and the bigger bolts are too big for the block?

FIL

Spartan!!
He means accessory bolt holes not head to block bolts

See, told you I was stupid!!!

Thanks

Fil