360 to 408

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74swingerlover

74swingerlover

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I am doing my first build. Picked up a running mild 360. It needs a rebuild before I put it in my car. My intensions are to go from 360 to 408 because I have heard nothing but great things about power/cost of the 408. I hope to get anywhere from 450-500ish hp out of it. What do I need to make this happen? I should say that I will also be running pump gas and eventually adding a 150-200 shot of giggle juice down the road.

I am also thinking about a 4-speed automatic because I live in the country and would like not to kill my engine. can anyone steer me in the right direction there as well?
 
74swingerlover said:
I am doing my first build. Picked up a running mild 360. It needs a rebuild before I put it in my car. My intensions are to go from 360 to 408 because I have heard nothing but great things about power/cost of the 408. I hope to get anywhere from 450-500ish hp out of it. What do I need to make this happen? I should say that I will also be running pump gas and eventually adding a 150-200 shot of giggle juice down the road.

I am also thinking about a 4-speed automatic because I live in the country and would like not to kill my engine. can anyone steer me in the right direction there as well?
Click to expand...

That much NOS is going to be a block breaker! You can safely add 100HP to a nice 408 pump gas build, but not much more without over building the engine.
We're doing a pump gas 408 right now for CarCraft magazine and it should be between 450-500HP with RHS heads and hyd. comp cam.
It won't be out for a while but once we've dyno'd it I can help with combo (headers-intake-carb).
Most of them we build are 500HP and more but not under 5K.
Brian
 
you guys are using the RHS iron heads?

with aluminum heads readily available at a reasonable cost, why not go to a larger aluminum head?
 
mopar340dave said:
you guys are using the RHS iron heads?

with aluminum heads readily available at a reasonable cost, why not go to a larger aluminum head?
Click to expand...

BUDGET!! WE sell them for 1295.00 with 8mm Ferrea 6000 series valves, all machine work done, 2.02x1.60 with the bowls cleaned after the valve job, Comp beehive springs for up to .600 lift!

There is no QUALITY aluminum head that can compete with these heads and they flow 268cfm at .500 lift on my bench and 272 at .550!
 
I guess that sounds about right.
They come needing a bit of work to make them usable with higher lifts...between that and the parts, I guess it adds up quick.

How much more would a similar setup in aluminum (Edelbrock) be?
 
ou812 said:
BUDGET!! WE sell them for 1295.00 with 8mm Ferrea 6000 series valves, all machine work done, 2.02x1.60 with the bowls cleaned after the valve job, Comp beehive springs for up to .600 lift!

There is no QUALITY aluminum head that can compete with these heads and they flow 268cfm at .500 lift on my bench and 272 at .550!
Click to expand...

do you have the flow numbers for them? and is this with work or no work?
 
Depends on how you set the eddy heads up...I shim the springs usually to up the pressures, and between chamber mods and valve job your looking at 2000.00 for the heads with work to them.

On the RHS heads we hone the guides, machine the spring pads down for .600 lift, machine the guide down for the extra lift, do the valve job, set spring heights, surface the heads, backcut the intake valves and do a bowl blend from the bottom cut to the casting!
We can sell the heads with anywhere from 62cc chambers to 67cc depending on the customers needs.
 
My 408 stroker has the following:

-Mopar perf. Cast crank, cat forged h-beam rods, KB forged 10:1 pistons
-eddy heads, hughes stage 3 porting, 208 intake valves,
-victor 340 manifold port matched/ 750 mighty demon carb
-hughes hydraulic roller cam and lifters 576/576 valve lift 252/258 duration @.050
-milodon gear drive
-hv oil pump/7qt oil pan
 
ou812 said:
I can post them next week. This is the way we sell them with the work described above.
Brian
Click to expand...

I am also interested in these RHS heads. $1300 for a pair sounds like a good deal if they will flow as good as the Edelbrocks. I can handle the few extra pounds of the cast iron.
 
Just found some flow numbers in the RHS LA Heads thread. http://www.forabodiesonly.com/mopar/showthread.php?t=84451

"We here at RHS have not done an official flow test on the heads, however INDY Cylinder heads did and these are the numbers they came up with. Again these numbers were not flow tested by RHS on our flow bench. "

Intake Exhaust
80.7 @ .100 75.6 @ .100
134.5 @ .200 135.4 @ .200
189.8 @ .300 174.8 @ .300
235.6 @ .400 193.7 @ .400
250.5 @ .450 196.8 @ .450
263.1 @ .500 198.4 @ .500
266.7 @ .550 198.4 @ .550
267.9 @ .600 196.8 @ .600

4.030 bore, 8mm stems 2.02 1.625 valves
 
ou812 said:
BUDGET!! WE sell them for 1295.00 with 8mm Ferrea 6000 series valves, all machine work done, 2.02x1.60 with the bowls cleaned after the valve job, Comp beehive springs for up to .600 lift!

There is no QUALITY aluminum head that can compete with these heads and they flow 268cfm at .500 lift on my bench and 272 at .550!
Click to expand...

[sarcasm]Oh well I guess you must have a happy bench, because my stock edelbrock heads flow more than those. [/sarcasm]

hehe

I bought a set of RHS/Indy heads immediately after seeing the out of box flow numbers and realizing what could be had with so little extra work.

But in a couple of the other boards i am on where everyone has the same set of stock 1500 dollar eddy heads on an efi truck with a worthless "computer friendly" cam, I was ridiculed for breaking away from the herd by buying a "cheap set of iron heads that are no better than an r/t head".

Sometimes the last laugh doesnt have to be a laugh at all.=P~

The money I was able to save with this great set of heads put me into a brand spanking new quick fuel 850 annular. And I didnt settle for less. I just payed less.:cheers:
 
ou812 said:
That much NOS is going to be a block breaker! You can safely add 100HP to a nice 408 pump gas build, but not much more without over building the engine.
We're doing a pump gas 408 right now for CarCraft magazine and it should be between 450-500HP with RHS heads and hyd. comp cam.
It won't be out for a while but once we've dyno'd it I can help with combo (headers-intake-carb).
Most of them we build are 500HP and more but not under 5K.
Brian
Click to expand...

I was playing around in camquest the other day to see what it said a 100 shot would add in torque to a 408...what I saw scared me.

I have been told that it's pretty accurate, but I am not sure.
If it is, it's no wonder why you see that as the smart limit.
 
I'll post OOTB Eddy flow #'s vs. our RHS heads OOTB from us to give you an idea using the same bench and bore (4.030).
I like the eddy heads, use them alot but these RHS heads when done properly are more affordable and will make more HP than the eddy heads OOTB!
I don't think the RHS heads will replace the eddy heads by anymeans, that's for sure but they do fill a void where using stock J heads that do tend to crack, and cost is in the 500-700range for rebuilt heads and lite port work and they won't come close to these heads in performance between the better ports and chamber.
 
I think so long as they use the LA rocker gear and intakes, you're getting a very good deal. Unfortunately IMM is on the wrong coast for me...lol. It's just less of a good deal.
 
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