i have a holley 650 double pump for a 13b 4port.12a side plates with gsl-se middle plate,racingbeat exhaust.the engine have extended ports,it will have a direct fire ignition,T2 oil cooler and some other extras as the money come's in but i don't what size of fuel jet should i use for the low's and high.i will appreciate if someone can give me an idea of what size shoul i use. https://www.nopistons.com/forums/pub..._DIR#>/dry.png

You could try 57 jets on the primaries. Not sure what the secondaries need. Possibly 59-61?



I could be way off though.

thank you i will try 61 on the secondaries.i'm still buying parts but when the engine was stock i tried i believe it was 52 on the primaries and 57 on the secondaries and it wouldnt start thank you again.