RPM vs. stock Manifold

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Rocket

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Looking for your input on using an Edelbrock RPM (not the air gap) versus the stock 1969 340 4 barrel manifol on my soon to be built 69 340. I have both manifolds. The engine will be used in a 4 speed Dart with 3.23 to 3.55 gears and near stock engine. I plan to clean up the ports a little (stage 1), put a close to stock Hughes hydraulic cam (either the 215/223 or 219/228) and near stock 10.5 compression. I will use the hi performance exhaust manifolds and 2.5 inch TTI exhaust. Carb will be the stock carter 625 cfm unit.

Which would you run?
 
RPM - no question.
As for cam, with stock stamped rockers you will likely run into interferences with lift over .480" even though the duration is in the range you want.
Maybe consider the CC 20-309-4 which is 222/226 and .464" vl. 3.55 gear if you are running a 26-27"dia tire.
If you go to the TTi headers you will probably add another 25hp to your combo - food for thought.
Get a bowl hog cut to get rid of all the material that is left after the 3 angle cuts and then blend into the port. Gind a bit of the material away from the push rod pinch point to improve air flow and try and make sure the head intake port entrance is a tad larger than the manifold outlet port to prevent any port alignment obstruction.

Any pics?
 
Just out of curiosity, with 10.5 : 1 compression, what kind of fuel will you run?
The reason I ask is I'm planning a 340 rebuild and would like to do the same, but plan to lower it so I can run pump gas, unless I put out the bucks for aluminum heads, in which case, I'm told 10.5 might be OK.
Arlie
 
RPM all the way. I'm switching from a M1 single plane to the RPM to make the car a little more streetable. I'm running around 10.1 comp and plan on tuning for 91 pump gas.
 
I will be running crane roller rockers so lift will not be an issue. In Canada I will use 94 octane unleaded. 9.5 to 10.5 is th CR I will run depending on final piston and gasket choice.
 
Idaho said:
Just out of curiosity, with 10.5 : 1 compression, what kind of fuel will you run?
The reason I ask is I'm planning a 340 rebuild and would like to do the same, but plan to lower it so I can run pump gas, unless I put out the bucks for aluminum heads, in which case, I'm told 10.5 might be OK.
Arlie
Click to expand...

opps!!!!!!!!!
 
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