360 LA vs. Magnum for stroker build?

I have a nice low mileage complete 77 360 removed from a motor home. I am also going to be removing a high mileage 360 from a 91 truck (Magnum motor?)that is being parted out. Dad really wants to build one of the 426 cu.in. stroker 360's using the Hughes kit for the 69 Dart. (I don't agree with it but it's his car) Which platform is the better one to use?

91 model would still be a LA block also but it does have a factory hydraulic roller cam setup so if you plan on running a hydraulic roller cam for that reason alone I would go with the 91 model.

Also the 91 should have 308 heads if you plan on running factory heads they are better heads than the early heads were.

I wasn't sure when the LA blocks were replaced with the Magnum...being 91 I took for granted it was the Magnum motor. Thx...

1991 360 is roller, non-Magnum (still LA). Magnums have many small advantages. Only thing to watch out for is that some of the '80s-'92 LAs were "further" lightened at the bottom of the block - wet head screws! I'd avoid that if possible.

Rick

The 91 360 block is stronger, especially in the bottom of the block where it has more meat not less. It also is roller cam ready, $100 for a regrind where a roller in the old block would set you back $1000.

I do agree about better sealing on a magnum.

Heres proof.

https://board.moparts.org/ubbthreads/show...rue#Post8365324

With what you have already, I'd use the '91, especially if you have the 308 heads. If the 308 heads are gone, I'd upgrade to closed chamber Magnum heads on the same '91 block. You'll pick up about 1/2 point compression on a 360 with Mag heads, IIRC. 308 heads are scarce now (low production then, 3 year run??), if you have them, you may be able to sell them to raise money for what you want.

I'd go with the block that sonic checks better. The later blocks seem to have better machining and that may(or may not ) save you some $$. The hyd roller upgrade(NOT really a performance upgrade,but for a mild street car is not a bad move) is about 650.00 on an LA block. The later block if it sonic checks good would likely be a good move. Depends.

I'm intrigued now as to whether or not it has the 308 heads. May have to get it removed sooner just to check it out. Thanks for all the info...it's appreciated.

There are guys out there who will pay stupid money for a set of 308s, sell them (I have sold a couple decent sets for $300)then put another $300 with it and get some EQ magnums. The 308 is basically a magnum with crappy chambers, small valves, big chambers, heavy valves, wet ex bolts, 1.4 ratio rockers, 5 valve cover bolts instead of 10 and a rough cast valve cover rail instead of machined smooth = leaky, low powered magnum. The EQ is a magnum on steroids.

I have a cam in a 5.9 magnum 208@.050 with .514 lift, it makes awesome power anywhere in the power band and a similar grind can not be had in flat tappet.

Magnum.