I'm plannig on putting a P90 head on my 75 L28. What modifications do I need to make to the P90.

Thanks,

Michael

None. It will bolt right on. But then theres issues with compression ratio to consider.

What issues? He'll have a lower a compression ratio which won't do anything but loose power. Given the great flow numbers from a P90 it might even out so you'd be getting nothing for doing the swap.

Most people who install the P90 Head on a early 280 are looking to go Turbo, due to the low Compression Ratio of appx 7.38:1. When installing the P90 head on a F54 Block or N47 block with flat-top pistons, the usual move is to cut the head .080 and use the N42 or N47 head valves, which are .080 longer, while shimming the cam towers the same .080 to achieve appx. a compression ratio of 9.8 - 10.5:1. Hope this is what you were looking for in the way of information.

Thanks to everyone who took the time to reply. As I have been looking into this ecp48 seems to have the same information as the majority. I'll give it a try and post the end results when I'm done.

Thanks agin,

Michael / MC75Z

San Diego, CA

What issues? He'll have a lower a compression ratio which won't do anything but loose power.

Exactly. not much of a performance modification.

Michael,

I don't know which head is on your motor currently.

If you have headers currently and you have round port headers, go with the P79 head. It flows just as well as the P90 unless you are looking to have head porting done. You may find the P90 better if you plan on getting radical.

If your early L28 has rectangular exhaust ports, never mind.