Anyhow, as far as tuning goes I don't like to make specific jet/rod recommendations and for several reasons. Number one folks just "google" up the sizes and look elsewhere for the cheapest possible price on them, or they dig thru boxes us used parts to find them and in almost all cases they used jets are "egged" out some from use and the metering rods worn down from many thousands of cycles. Currently there are 4 different profile jets being sold for the Q-jets and 3 of them don't work as the depth of the orifice and angle leading up to it is incorrect. So I give up details, a guy runs out and buys the parts elsewhere, gets poor results and doesn't know exactly why?
Good results start with the right parts and parts that are within spec, so I try to help out there as well. For all the early APT style carburetors I push folks building them to install our custom machined external APT screw. Then we can supply jets with tapered metering rods which will give them full control of part throttle A/F from rich to lean without having to take the carb apart and change parts.
I also have specific power piston springs custom wound for any application and we supply one with the tuning parts. I insist on a new secondary cam/spring and supply them in our kits as well (except the "basic" kit). So basically the service I provide here is to have customers supply all their engine/drivetrain/vehicles specs, tell me what carb they are going to use, then I supply them what they need so it's basically "plug and play".
Also be aware that I REQUIRE all the engine specs to make accurate recommendations. Things done with the engine build to improve engine efficiency may require LESS fuel. These include higher compression, tighter quench, better combustion chamber shapes, improved port flow, and good cam selection. So if anyone reading this wants specifics for tuning, be ready to supply specifics on your engine and I'll nail all that down for you........Cliff
