Can anyone give me an idea of good jet size to start with in a Holley 650dp with proform main body, on a 327 10.2:1 8000 rpm engine. 6spd Manual t56, 3.73:1 rear in 89 Camaro. Jets #72 #84 came with the proform main body, but I think they are way to big.

 

Start with 72/84 jets. Tune from there.

 

My 650 DP that I upgraded with a Proform main body loves the 72/84 jets. The only changes I made from stock were the secondary high speed air bleeds, I went down two sizes. Have you tried it yet with those jets?

 

No, I´m still waiting for my diff to be installed...

I´m new to carb building...
There were two #36 airbleed jets included with the main body, And it said on the package "use these in rear if your carb has two idle air screws". Mine has two idle air screws up front and none in the rear. Than I should use those smaller jets? Do some holleys have only one idle air screw or do the mean if it has screws on both front and rear?

 

Some holleys have a "four corner idle" system, which has two screws on each metering block.

Based on your observation of no idle screws on the rear metering block, go with the #36 air bleeds.