Hi there, i was just wondering if a FRST Throttle body will fit a RS1800 inlet manifold?

Reason for asking is i have a RS1800 inlet here without TB and can get the TB off a mates RS1800 but will need to put something in its place so he can still drive the car...so i have been offered a FRST one for a tenner so just wondering if it will fit with no issues?

thanx

bassboy