Hey guys…..A few questions that I have after extensively looking up a lot of Engine Quest Magnum LA bolt pattern / Magnum head swaps on the net.

My current engine is a J headed 360 chamber size from what I read is 71cc chamber. The short block has a stock 3.58” stroke, zero deck, speedpro pistons 4.030 / 10cc, felpro1008 head gaskets yielding a .39 compressed size. Crane 272 advertised duration cam.

So on a comp ratio calculator the present setup yields 9.18.

I check out the Engine Quest magnum LA and from what I can find on the net its 62CC so we are now looking at a 10.33 comp ratio.

In the Tech page the LA/Magnum write up, the guy says he is using a 268 mp cam (pretty much the same as mine) and 10.6 comp ratio and it runs fine on 92 pump gas.

Question #1: I think that’s a pretty high pump gas compression ratio but are the magnum combustion chambers that good that this is ok?

Other general questions not mentioned:

Question #2 Head gaskets: 360 or magnum?

Question #3 Spark Plugs: 360 the same as magnum, anything special?

Question #4 Pushrods: As I am using the LA rockers found on the EQ conversion head, do I still need those special 7.625 length pushrods, (MP Part number: 5007477 or the summit chromemoly brand that was mentioned)? If so is that due to a possible head height difference? I also don’t need the oiling type pushrods for pedestal rockers as I am not using them, so is there a solid version of this pushrod (I don’t think it matters though).


Question #5:
Dealers for OE 318B heads: I have seen them mentioned here on Moparts. That Clearwater Cylinder Inc (on EBAY# 370124447607) sells them 700 a set, Carolina Machine engine (CME) and that fast 4 speed guy. Are they ok dealers?

Question #6: Some people state the LA valve covers may work on the Magnum; if so what gasket is good for this?

Question #7 (Last one). I got 340 manifolds, somebody suggested on moparts some remtek or whatever gaskets kept it sealed up as there is a port mismatch.

A lot of question I know…sorry.

Thanks
Sean