Dylan,

I would prefer the B23FT. However, these engines were only offered in the 1984 760 Turbo, so they are a bit harder to find. These engines have a very strong bottom end and also have the larger 2.3 liter displacement. The B21FT (from the 240 Turbo) is very similar in construction, but has only a 2.1 liter displacement. The B230FT (1985- 7xx Turbo) is also a very good engine (replaced the B23FT; 2.3 liters, but a slightly weaker bottom end that that of the B23FT). The B230FT is usually the most common in salvage yards. Anyway, any of Volvo's turbocharged 4 cylinder engines would be a good, strong choice. I hope this helps...