I just picked up a 600 double pumper for my 355. The 355 is a mild build, 9 to 1 with small valves, RPM intake and the cam is in the .450-.460" lift and 272-278 duration range (don't remember exact specs & lost the cam card). Right now the carb has 74 primary jets and 76 secondaries which I'm thinking will be a little much for this set up right now.

Start with the factory jetting and tune to what the engine wants. They should be pretty close.

72 prim /76 to maybe 78 as a conservative starting place but you may need to fatten it up,plug readings and how it runs will be the deciding factor there.

But make sure the timing is right 1st before tuning the carb,a good place to start with that aftermarket cam your running it is approx 16-18 deg base timing + 20 deg mech in the dist all in by 2800 rpms for 36-38 total . But you still may need to dial it in a little better for best performance but that will be a decent place to start .

For street vac adv hooked to full intake vacuum all the time would be usefull with that cam too.

Scott

I would start with the stock jetting which is 66 primary and 76 secondary.

Dave

FYI,66 on the prim side is fairly lean for a 355 with a mild perf cam & AL intake & likely (but dont know for sure) better then stock breathing ex system too,may even have headers too but he didnt give us the exhaust nifo.

I would start with a min of 70 (maybe even 72) prim jetting for mild perf cam'd 355 with AL intake .

just my 2 cents

Scott

Yeah Scott, I'm running full length headers and will be running the 2.5" 2-chamber Flowmaster system. I'll run it as is for starters I guess and then tune it from there. My main concern was it being way over jetted when initially trying to fire it up.
Thanks guys.