Hi guys I have a new Vavle body for the C4 and it has a green spring.... can any one tell me if it is stage 1,2 or 3???? and I cant get the VAC secondaries to work on my 750 Holley ............ any thoughts???? I would like a 650 DP for it if any one has one...

How are you test the vac secondary on the carby?

It will not open while free reving the engine.

yeah they work but only at 5000rpm

hey mate on the holleys they have the vaccum secondries and they have different spring tentions, which you can get from holley, i had the same problems with mine on my commodore, i put a lighter spring, white i think and the secondries came on at about 2000 rpm, holleys take alot to set up but the are a simple carby, are your floats set right. Also the thermo quad is quite a tricky carby to rebuild but when they are set right they will throw you in the back seat. Try differents tentions on your springs