Alright, here's my deal. I picked up a mid-70s quadrajet at a swap meet for like 25 bucks, and am half-way through rebuilding it. I'm planning to run a 270/270 470/470 cam and 1.6 rockers, in a port/polished 305 with an edelbock performer air-gap, 1" phelonic spacer, and a hood scoop (for cold air). is there any way i can know before i put the thing back together and put it on the motor what size jets i should use? i know almost for certain they wont be stock, any ideas or suggestions?

thanks a bunch

 

What jets and rods does it have now?

 

I'm not sure. The jets in the kit are most likely stock but I don't know what size, and I don't think they included new rods in the kit, so those would be stock for sure. How would I tell? Do I measure them with a caliper or something?

 

Jets and rods don't come in a rebuild kit. They assume you'll put the originals back in.

The jets are numbered. The rods are numbered with a letter. The secondary rods have two letters, and the secondary rods hanger has a letter stamped on it.

Might not hurt to have your carburetor number as well.

 

The secondary rods are a CH, the jets are a 9, the primary rod hanger has a 9 on it, and the primary rods have 48K on them. The secondary hanger has a K on it.

 

The primary jets should be a 2-digit number. It's the jets and rods together that determine the jetting.

The K hanger is a fairly lean one. Going with a lower letter usually helps.

 

The second digit is horribly faint, but I'm going to say it looks the most like a 2. So the jet size would be a 92?

Also, if I were to get a jet kit, would I want the 1/4-32 or 6/32 size jets? And about the hanger, what would you recommend?

 

You need quadrajet jets.

92 doesn't sound right. 76 maybe.

B hanger is pretty popular.

 

Oh, yeah, I could have been looking at them upside down. Right-side up would be with the numbers on top then. In that case it would be a 76.