sr20 on my tranny?

I just recently bought a 1990 240sx coupe…I am absolutely in LOVE with it. My question is tho, the guy I bought it off said that he would give me an sr20 with the car but with no tranny for a bit more money. He said that I could use the tranny from my stock SOHC 90 on the sr20…I dont know if this is true or if he is just trying to sucker me in. I said I will think about it and ask you guys…So please help me out guys! is this possible, or just crazy talk? Thanks!

The “guts” are the same…but you will still need an SR20 bellhousing to bolt it up to the motor