Is it this cam?
Ovalport heads? Dual plane intake? Carb?
I wouldnt change both gears and to od just one of them. No problems running 2500 stall converter with 2100 rpm if its good quality and you have a good transmission cooler.
I was in same boat some years ago. Wanted to use car on longer trips vaccation with wife and kids.
Thought of Gear vendor or 4l80e but felt both was to much money.
Went with 3.31 from 3.73 and the drop in rpm was enough for me. Considered 3.08 but decided 3.31 was better for my combination. No noticeable difference in performance with 3.31.
I have a 9.5” converter with 3000 stall and noticed zero difference in behavior. Has used 2500 stall with 3.08 in the past worked just as good as with 3.73 with a sb.
489 10.5 in comp, brodix race rites, edelbrock RPM air gap, pro system 1000hp, 242,[email protected]
.621 .616 112ls.
Th 400 with 9.5” 3000 stall converter.
275/60-15 so 28” tall tires.
Even dropped fuel consumption.
Highway 12-14 mpg with 3.73. Highway 16-17 mpg after change to 3.31.
With your smaller cam and shorter tire I would consider a change to 3.07(3.08 aftermarket) think it will work very good even though you have less cui than me if you dont mind loosing little performance. I recomend US gears they are the best brand. With all import gears some shops refuses to use anything else since they can give all kind of problems.
You dont know someone you can borrow a set of wheels with 275/60-15 or another dimension with 28” tall or taller tires from? It will put you between 3.73 and 3.08 in rpm and give you a hint.
If you can afford and dont want to loose any performane go with gear vendor over th700 with your combination imho.