SpeedMaster Heads for a 5.9 Magnum
The iron heads SpeedMaster has are bare. Was wanting to get a set ready to go I know they would need checked. Could I run the aluminum heads on a setup like this? Would I have to use a different rocker set up?
They are 1.92/1.62
150cc intake port
60cc exhaust port
The stem size is 8mm, stock magnum.
They peak 245 cfm, but the low lift numbers are horrible, garbage.
You cannot run this head ootb.
It needs some deshrouding ,stones, hand blending. Itll do great after that.
If you use use 1.94/1.60 11/32 valves, yes you can cut 1.60 from 1.62, itll do about 260cfm intake and 212cfm exhaust with the right blend port work. Exhaust work is minuscule with a radius seat job.
62 cc chamber ootb iirr.
Stock chevy length is about a drop in with stock rockers in a magnum. The +.100 stems @5.025/5.011 will yield a spring height of around 1.725 . If going the +.100 route and using stock pushrods, geometry aside, will require a 5/16 .065 thick hard washer under the rockers pedestal bolts if a magnum short block is being used.
I'll be posting some numbers for 2.02 versions I've been working on for a memeber here soon.
Speedmaster lies, so dont believe the site info on them. They are not 179cc.
If they were...you would be able to read many threads on them because there is a market for an iron magnum head with the loss of rhs/eq. They are somewhere in the 'like a eq' bracket so far..
