Re: Starting line ratio too steep?
 

This is a 28 x 10 bias 3.875 x 4.185 427 23 degree sbc 3250 lbs factory chrome bumpers all steel roll up windows 69 Nova has been 1.27 60 with a 8,45 SLR powerglide 1.69 low 5.00 final. Shifted 7300rpm.

I think I'd leave the 4.30, depending on speed, you may cross around 8000 in second gear. Or you could do a 4.10 to cross 2nd gear 1/8 mile.

https://i.imgur.com/N4D74mn.png

https://i.imgur.com/9z8wpE3.jpg

Re: Starting line ratio too steep?
 

I actually thought about a Proflite transmission at one time to gear it the same with a 4.56 gear for 1/4 mile. This car has dipped in the 5's N/A. I ran it to the 1000 ft 8000rpm and coasted 9.59 118 mph with the powerglide 1.69 .500 final.

All this kinda apply's to what you're doing Op. With your weight you'll probably run similar numbers.

Good luck!