Hi guys so I installed a Howard's 473 lift camshaft in my 225 also milled the head and now have 9.1 compression, I'm currently running a super six two barrel carb to a single 2.25 pipe question is would I benefit adding a Holley 390 to my set up and a dutra dual up front? And would I lose economy

I would do the Dutra exhaust first, as that will help both power and economy. Holley 390 may or may not help either. Likely you would get worse MPG and depending on tuning you might get better power. The supersix carb, if in correct tune, does very well for both power and mileage with a mild motor such as yours.

Here are a few questions to help with setting your car up right. Can you post your cam specs? What is your compression ratio? Did you "degree" the camshaft when you installed it? What valve lash did you use?

Lou

_________________
Home of Slant6-powered fun machines since 1988

I have 9.1 Compression, i did not degree the camshaft just lined up the dots on the both gears, my valve lash is set at 0.22 hot in and ex
Advertised Duration Intake - 255
Advertised Duration Exhaust - 255
Duration at .050 Intake - 220
Duration at .050 Exhaust - 220
Valve Lift w/OE Ratio Rockers Intake - .473
Valve Lift w/OE Ratio Rockers Exhaust - .473
Lobe Seperation Angle - 110
Intake Centerline - 106
Valve Lash - 0.022

Car has a real nice idle i had to retard the timing a bit, really pulls hard and smokes up the tires with the 4 speed and 3.55, to bad i just busted a tooth on a ring gear today sucks.

You really should degree the cam. There is a 50/50 chance that it is anything close to where it should be. That being said, if it runs well I would not pull it apart and degree it.

I am running that cam in my back-up race motor with a 600 Edelbrock because that is what was on my big bore engine. You would be fine with a 500 Edelbrock or stay with the BBD. You can run the Holley if you like but they do take a bit more tuning.

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

If it is running very well, then I would not take it apart. 9:1 comp should work very well with that cam, as it sounds like it does. I would do Dutras and 2X2" head pipes into 2.5" Y-pipe (Flowmaster Y or similar, no muffler shop cobble up) just behind the trans X-member then single 2.5" out the back and see how that improves things.

Enjoy!
Lou

_________________
Home of Slant6-powered fun machines since 1988