Spitfire, You will not NEED an adaptor plate but a spacer will solve some issues as the input shaft on a T-5 is longer than original trans and will need attention and an adaptor takes care of that. Also I'd suggest reading ALL tech articles on this swap here and over on Inliners.org site.
My spacer plate is simple but has some imortant details. Like a lip on the front side that keeps it dead center in relation to the bellhousing, where just a 'spacer' does not.
Also you may want to contact Buffalo Ent. ph. 360 652-7684, makes adaptor plates and surely has ALL the answers on this and rear end swaps et.
Best of luck
Jim
