DadsApache, strenght isn't a problem with either trans. Main issue is 1st and 5th gear ratios. Ratios are all over the board for both 4 and 6 cyl trans. Most import to get the tag or sticker number and use the net to determine ratio's.

One common referenced site is; http://www.britishv8.org/articles/borg-warner-t5-id-tags.htm

The number you need will be 13-52-??? no others will help.

If you plan to run a mechanical speedometer you need to stay older than 86?, I could be off a year there.

Lugnutz (member here) also recommends turning input shaft and counting output shaft turns to absolutely test ratios. For a stockish engine I like a 1st gear in the high 3's low 4's with an overdrive ratio of 0.72.

Good Luck,
Ron

RonR


1951 3600 with Clark flatbed, T5, 4.10 rear
1970 340 Duster
1990 5.0 V8 Miata (1990 Mustang Gt Drivetrain)
1964 CJ5