Aha! a 380Magnum
This engine comes with a 9.0 CR, 288/292/108(I think) cam. and an M1 Singleplane intake and is not for use with A/C. lol.
Question #1 is why are you hobbling it with a 3.08x2.66=8.19 starter gear?The minimum roadspeed with this combo is about 8 mph, an unless your tune is perfect, it WILL be jumpy.
That camand intake combo wants about an 11/1 starter, minimum 10/1. That would be 3.73s to 4.10s with the 2.66 low box.
So first things first; you need a perfect tune, then if still jumpy, get a different intake, then if still jumpy,get some bigger gears in the back. But 3.55s, say will only get your minimum roadspeed down to 6.8 mph,still with a perfect tune.So the next thing would be to get the 3.09 low box.This would get your minimum roadspeed down to 5.8 mph.
Are you seeing why guys run automatics with big cams?
So, you need to get the tune dialed in;JOB #1.Or spend a lot of money to move the jumpiness down 2.2 mph, can you hear me chuckling? See, That's what I did; I spent a lot of money to get the jumpiness down to 4 mph.
But first we need to talk a little more about second-gear jumpiness. This is highly unusual.
Question #2; At what rpm or roadspeed does this second-gear jumpiness take place?
Question #3; and yet TBA is the flywheel weight?
So where to start? That's easy I always start with the T-port sync.
