dustoff440
Well-Known Member
what kind of hp gain would you get on a mild 360 magnum by installing out of the box RHS iron heads??? I saw a dyno test with Edelbrocks and they were worth 50 hp
I'm not the expert but it seems to me the power gain from just a head swap is going to be far less than what the heads make possible with the right cam and other parts.
So can anyone give a rough breakdown for horsepower gains?
Stock 5.9 upgrade heads only 20-30hp give or take the assembly - I think Indy is the only place to get them now too, and they come bare. So if a performance shop gets them, does a good modern valve job,and uses the right parts I don;t think 30hp is far fetched with no other changes.
Add cam upgrade. - Need to have a cam design to even consider and it's dependant on the intake, heads, and exh manifolding choices.
Add intake/carb. - - Another 15 - 25hp with intake alone. Carb's fine IMO
Add headers/exhaust. - If you have manifolds now - an easy 25-30hp with headers and decent 2 1/2" pipes w/good mufflers. If your exhaust is stock now, closer to 10-15hp.
The comp cams simulator does this but not sure how accurate that is and I'm not sure how to input a stock cam.
Whats your goal with the car ? LXGuys Dart is running 11s with a pretty mild 360 Magnum. He has EQ heads a small cam and a RPM Air Gap
Whats your goal with the car ? LXGuys Dart is running 11s with a pretty mild 360 Magnum. He has EQ heads a small cam and a RPM Air Gap
I think hes saying the rpms were 50hp better then stock magnums on a dyno test. not 50hp better then the rhs heads
Street car, I'm hoping for 11.90's thru the mufflers with a 150 shot of gas. I'm thinking that after drag/friction that I will have 425 hp or so at the wheels
If I had it to do over again, I'd go with less lift on the cam. Its got (EDIT .544, and that's just too much. It causes valvetrain issues, puts a hurting on the springs, and I cant get the cool Hughes shaft rockers because they're 1.65 ratio. I bet if I had .525 lift the power would be exactly the same.
I would also have the heads machined for better springs than the ones Hughes provides (though to be fair I didn't realize they had to be machined for that when I bought them).
The cam is a custom grind hydraulic roller. Heads are as-cast from EQ or wherever Hughes gets them. No porting, no milling. I've got to say, I've been pretty impressed by them-especially for the price.
Cam is 224/230 @ .050. The stall is right around 3800. I've only been launching at 2400.