different magnum heads produce what?

[71dustar]

im a ways away from rebuilding my engine but id like to know what's a rough estimate of horse/torque for the different magnum heads on a 360:
1-stock
2-ported stock
3-eddy rpm heads
4-ported eddy rpm heads

 

[AdamR]

The stock heads are good for just over 400hp.

 

[71dustar]

so i could port the stock heads and make 450 without spending $1400 on aluminum heads?

 

[AdamR]

Ported heads should make 450hp with out problems. Just make sure to magnaflux them first. Magnum heads tend to crack between the valves.

 

[63dartman]

Another option would be the clearwater magnum heads. Thicker casting and better than stock flow.

http://www.cylinder-heads.com/details.cfm?itemid=1705

 

[sharpie]

you're gonna have to be careful about porting the stock alum heads. The intake pushrod position results in a smaller limit on intake porting. Personally, I'd go with Eddy heads for three reasons:

1. thicker casting
2. Chevy-style stud-mounted rockers
3. can go over .52 lift, unlike pedestal-mount stock magnum heads

If Hot Rod Magazine has taught me anything, it's that with a Comp XFI cam and new lifters and pushrods, you're going to make about 100 more hp over stock.

 

[68 Sedan]

What size valves in the clearwater heads?

 

[deman360]

If you use flat tappet lifters you will have to clearence the push rod holes on the heads. Hughes engines will tell you this also. Straightline Performance seems to have the best price on Eddy alum. heads magnum and perform rpm.

 

[dgc333]

so i could port the stock heads and make 450 without spending $1400 on aluminum heads?

If you read the Mopar Muscle engine dyno challenge from a few months back the top three finishers got over 500 HP with ported magnum heads on 408 sb strokers.

 

[71dustar]

i do plan on stroking my engine. just curious as to what heads i should get and what to do to them since its my first building an engine and id like to do most of the power options now then have it installed and in a few years add new heads or what not.

 

[dgc333]

I keep hearing that you have to clearance the push rod holes. I have magnum heads off a 99 5.9 liter motor on a flat tappet cammed LA block. The area where the push rods pass through the head is a wide open cavity and i can't see how there would be any clearance issues, certainly aren't on my engine. Maybe there are different casting used over the years.