Need advise on jets and power valve

[Stewsta]

I recently puchased a rebuilt 440 and the seller included a 750 Holley DP and Quick Fuel rebuild kit with the engine that hasnt been used in sometime. I went thru the carb with the kit and installed the 6.5 power valves in place of the plugs and also checked the jets which are 81's and 82's. I have no idea what kind of vacuum the engine was pulling before it was pulled from the previous vehicle. My question is are these jets and power valves a good place to start with the tuning? Im new to carbs and there are so many different set ups I dont know where to start. The engine is currently on the floor and awaiting install and Im just trying to make it as painless as i can trying to find a good starting point.

Engine is .60 over 440, holley 750 DP, purple cam 284/484, flat top pistons, edelbrock intake, stock 906 heads, 727w/ 2400 stall, 3.91 sure grip in a 66 coronet

thanks Stew

 

[moparmarks]

What is your elevation there in OK?

 

[Meep-Meep]

The power valve will be determined by engine vacuum at idle and with an auto tranny should be checked in gear. That .484 cam can kill your vacuum at idle, especially with stock below deck flat tops so you may have issues getting it to run right. I won't be surprised if you get a vacuum reading at idle in gear of around 5 or less. Do a cranking compression check to get an idea of what's going on. If you have a reading below 150 then time to do some drastic measures.

A standard Holley 750 list 4779 should not have 82 jets but perhaps 72 in the primary and around 78 in the secondary with no power valve in the secondary. The 82's were probably installed because the PO removed the power valve in the primary and this could be another clue that you have nearly zero vacuum at idle, and if so, plan on a cam change.

The altitude question should also be addressed, which in that case you will tend to go leaner.

 

[Stewsta]

My elevation is right around 1200 ft. I test drove the Charger that this motor was in before it was pulled and it idled and pulled very well. It had a QFT 750 on it when I test drove it. Once I got it home I did notice the plugs where showing quite a bit of carbon build up for a motor with 100 miles on it.