Originally Posted By GTX MATT
I would not go to 74s without at least trying WOT with the 76s first. IMO it will probably be pretty lean with 74s at WOT...


It WILL be lean at wide open after pulling that much jet out. And it looks like it still needs even less jet. The OP says that he needs to avoid WOT for now, so continuing to test the cruise with less jet is not a problem.

The idle is okay right now and he is moving in the right direction on the cruise. Keep pulling jet until the cruise is clean. Then, when possible, drop the secondary linkage and start drilling the PVCRs until the WOT on the primaries is good. Opening the PVCRs bigger will replace the fuel being taken out with the smaller main jets. And it will want that additional fuel sooner now.

We usually go with a 9.5 or 10.5 power valve. You really can't get too quick of an opening. The reason it didn't need that early of an opening point before is because it was so rich already. Now that it is leaner on the cruise, it will need the additional fuel sooner.

The track is the best place to set the WOT, but initially shooting for low 13s will get it close enough to dial in without being too rich. It is easy to drill it richer, but harder to lean it back down if the holes get too big.

We have done quite a few Holley 3310s and double pumpers this way. They are always rich on the cruise. Pull jet until the cruise gets happy, open the PVCRs until the WOT gets happy, and get the power valve open in time to eliminate any lean stumble has always worked.


Master, again and still