More magnum cyl. head help

Posted By: 1swingin

More magnum cyl. head help - 08/22/10 09:26 PM

Ive decided to use a set of magnum heads on my 85 360 to help bump up the comp. Ive decided on a comp xe274 cam. As I was pulling the magnum heads off at the junkyard I noticed the angle (or lack there of) on the intake bolts. I have an old school ld340 intake I was gonna use but I dont see how the bolts would work. Also, I was told to clean up the bowls and runners on the heads. Anyone have any pics of port work they did just so I can get an idea of where and how much I should remove? Thanks for your time!

Posted By: 70AARcuda

Re: More magnum cyl. head help - 08/22/10 09:45 PM

the LD 340 will not fit magnum heads..magnum intake bolts are vertical...

...also the magnum heads stock springs dont like lift over .500..the retainers hit the valve guides..

Posted By: cudadoug

Re: More magnum cyl. head help - 08/22/10 10:07 PM

Hey swingin...make sure them boneyard mag heads aren't cracked. The OEM heads seem to do that on a regular basis.

Posted By: 1swingin

Re: More magnum cyl. head help - 08/22/10 10:25 PM

I ran the motor before pulling them and no signs of being cracked. It was a low mileage truck that rolled down a hill. Alot! I pulled them off and checked them. I couldnt find any. Where do they tend to crack just so I know where to look? Thanks for the heads up!

Posted By: HotRodDave

Re: More magnum cyl. head help - 08/23/10 03:43 AM

Don't look too hard between the valves on the end cylinders, if you look hard you will find cracks there and not run the heads. Literally 9 out of 10 mag heads I have looked at have cracks there if you look hard enough but I have never seen one cause any problems.

I can, or any competant local machine shop should be able to machine the proper bolt holes in your new heads for a lot less than the price of a new manifold.

Posted By: TheOtherDodge

Re: More magnum cyl. head help - 08/23/10 04:01 AM

If you are going to use the Magnum style head, you will have to use a Magnum style intake, such as the M1.

Posted By: goldmember

Re: More magnum cyl. head help - 08/23/10 04:17 AM

Quote:

If you are going to use the Magnum style head, you will have to use a Magnum style intake, such as the M1.

Or drill and tap the magnum head and run an LA intake.

Posted By: patrick

Re: More magnum cyl. head help - 08/23/10 01:22 PM

Quote:

Quote:

If you are going to use the Magnum style head, you will have to use a Magnum style intake, such as the M1.

Or drill and tap the magnum head and run an LA intake.

what I did.....found a machine shop that rented time for $15/hr. took an hour to drill & tap on a bridgeport. note, the LA intake bolts are NOT perpendicular to the intake face, but 7 degrees less than perpendicular.

for springs, go to hughes get their retainers for magnums and their #1110 springs. if you want to save a few $$, go to a junkyard and find some retainers off of mopar 2.2 & 2.5L, and use them with the magnum locks and hughes springs.

if you get the heads redone, sink the valves ~.030 or so to get a little more IH & retainer clearance to the seal...

Posted By: vcummins

Re: More magnum cyl. head help - 08/23/10 02:14 PM

Quote:

Quote:

Quote:

If you are going to use the Magnum style head, you will have to use a Magnum style intake, such as the M1.

Or drill and tap the magnum head and run an LA intake.

what I did.....found a machine shop that rented time for $15/hr. took an hour to drill & tap on a bridgeport. note, the LA intake bolts are NOT perpendicular to the intake face, but 7 degrees less than perpendicular.

for springs, go to hughes get their retainers for magnums and their #1110 springs. if you want to save a few $$, go to a junkyard and find some retainers off of mopar 2.2 & 2.5L, and use them with the magnum locks and hughes springs.

if you get the heads redone, sink the valves ~.030 or so to get a little more IH & retainer clearance to the seal...

I have done this many times works great and you can run la or mag intake.