Hello, Does anyone know what the difference between the ARP 144-3604 and 144-3605 heads bolts are, they look the same to me, I have a set of 144-3604 and want to know if I can use them on Alloy heads, I have emailed ARP and have yet to get a reply. Thanks Bruce

ARP 144-3604 are oem lengths. Oem Magnum heads. ARP High Performance Series Cylinder Head Bolt Kits 144-3604 144-3605 are for the aftermarket heads that have the one bolt longer then the other kit. ARP High Performance Series Cylinder Head Bolt Kits 144-3605

Here is a photo of same heads I have, Mopar P4532900, are you saying alloy heads use 3 different length bolts?

Id toss it on your block and see if your oem bolts work as far as length, then you would know. Looks like they use two lengths. The center row would be where the height difference would be in the casting if any. Not a popular head really. How did you end up with them?

so where the head bolts go through the center they bosses are higher on eddy alloy heads? (eddy heads below) The ones on the MP heads look like they are machined the same as the iron heads, the eddy looks to be sitting up higher.

Yep. eddy like heads have different heights, and so does oem heads like j heads. But eddly like heads take one more longer in the 10 total then the oem la heads. But none of that pertains to what your doing. Thats just an al. mag head, the 3604 PN is the same as your oem bolt length im almost sure. But since your so far away id double check with your oem bolts.

Hang on, will your exhaust fit on those heads? look how far apart the center two bolts are. Just curious; what do the chambers look like?