318/ Magnum Head Conversion

The XE268 with the magnum rocker is .509/.512 lift. I am using it on my LA360/magnum hybred. I didn't need to cut the guiides but do check.

If your deck is stock and the magnum heads have not been cut down the MP conversion push rods that are 7.625" long will be OK but it's another area to check to make sure you have enough preload.

You shouldn't have to do anything regarding lifters since I am assuing you got new after market ones to go with the new cam.

The performer intake will not bolt to the magnum heads unless you have the heads redrilled to the LA bolt pattern. But, the small ports of the performer will not give you the full benefit of the heads. MP, Edelbrock and Professional Products have intakes that bolt to magnum heads the PP intake has both LA and magnum bolting provisions.

Your LA valve covers will work fine even though the mgnum heads have 10 bolt holes. I would recommend the MP composite LA valve cover gaskets though.

You can use either LA or magnum head gaskets but the intake gaskets must match the bolting (redrilled heads use LA gaskets). You will need new head bolts, the magnum heads use two lengths and they are different than the LA bolts.

The stock magnum valve springs are not acceptable for the XE268 cam. When I did this with the XE268 Comp didn't have a drop in spring and they recommended the MP R/T spring. This spring is a straight spring with a damper and won't work with the magnum retainer. The 2.2/2.5 mopar 4cyl retainer is the same as the one MP sells and is easily available at the local bone yard. Use the magnum locks though. There are other spring options now but you will still likely need new retainers.