The engine is new to me this year and I haven't run it yet.
With the engine that was in it 5.70s.
I was guessing more like 5.30s 40s with the added HP and will start the year with the 4.30s.
The reason for gear change is I have them so there wouldn't be any real cost involved to change them.
I dont have tires and we know how expensive they could be.
Did you notice any difference consistency wise with different size tire?
I am running an altered too. Last year I looked at my car. When I built it we were racing the full quarter mile in Super Pro brackets. Now almost every (insured) track has switched to eighth mile S/Pro racing. In addition, even the smaller mom-n-pop strips have taken to doing effective starting line prep for good bite. I'm using 4.30 gears and 12 x 32 slicks on my 1800# altered with an inline six. So I asked myself "why am I still running 4.30 gears and a 1.76 'glide and carrying a huge tire down track?" I need more gear and less tire. So I switched from a 12 x 32 to a 10.5 x 28S which not only increased my effective gear ratio but also reduced the rotating mass of my tires since each of the smaller tires weighed about four pounds less. I did not change gear ratios.
I picked up about .05 in the sixty and around .10 in the eighth.
My six cylinder is making about 550 HP on gas. It runs 5.6 / 5.7 in the eighth and 9.0 in the quarter.
With 650 HP I'm guessing you are running around 5.1 / 5.2 times. If your track preps the track why not try a smaller tire before switching to a taller gear?