LA 360 vs. 5.9 Magnum

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Gryzynx

Gryzynx

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Hope you all can help me with my dilema. I'd pretty well convinced myself that I wanted to go with a 5.9 Magnum in my 68 Cuda notchback. Reason is I wanted the roller cam, EFI and high flow heads. After much reading, I'm finding that the Mopar EFI is best swapped out for something like the MegaSquirt, roller cams can be installed into the older blocks and the old style heads with the shaft rockers may be superior to the Chebby style rockers on the Magnum heads. I'm also not too impressed with the HP figures for the junkyard 5.9 truck engines. Crate motors seem to fare better, but most of them are being put in service as carburated.

Now for my dilema. I have 2 carburated 360's, one is allegedly a late 70's police interceptor engine. It has an aftermarket intake and Holley 4bbl setup. The other is from a 1975 E300 based motorhome and I've got a 727 to go with this one. Both run. I've driven the motor home for about 200 miles and the engine runs sweet. Bought the truck from insurance salvage, using it as parts storage. I'm considering using either of these engines in my Cuda, eventually upgrading to aluminum aftermarket heads and roller cam. I'm considering a Victor jr. EFI manifold with a MegaSquirt controller, but for now I may just go with the intake/4bbl I already have. There seems to be no real reason for me to go the 5.9 Magnum route, particularly since the local salvage yards seem to think they are made of gold.

I'm a little short on recent experience, but I was very happy with the 2bbl 360 I stuffed in my first 68 Cuda 30 years ago. So, what are the pro's and con's?

360 police interceptor engine?

360 motorhome engine?

5.9 Magnum engine?

Thanks.
 
I did the Magnum swap and I love it! Change the cam, run a carb and just drive it. Good power and will last forever, You might want to pull the heads and have them checked first. They are pretty good about cracking between the valves. That's just my opinion though!
 
The magnums have taller lifter bores to support the roller cam. I had to go with a custom ground cam to keep my retrofit roller lifters from coming out at max lift and exposing the lifter oil groove. This was with a '71 340 block. And it is a common problem when installing a retrofit roller cam into an older block. Some people get lucky and drop one in with no problems, it just depends on how the block was cast the day it was made. The cam companies will all tell you they drop right in but that is not always the case. Plus the retrofit set up runs around $1,000 for cam/lifters. If you get a magnum you can re use the lifters and just change the cam. That right there is a good reason to go with a magnum block.
 
& you can get the factory magnum roller re-ground for about 1/2 what a new one will cost, i sent mine off to Bullet cams, it'll be between 125.00 & 150.00.

The only down side with the magnum are the heads, you can rest ashured most will be cracked, i opted for a new set of RHS heads & chunked the stock ones, i won't install ANY cracked head on an engine, even if it doesn't leak.
 
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