Here's what I found, measurements may be a bit off if your dealing with 1/4 inch clearances etc. Car is an 86 SE 4 speed.
Width:
At frame level, from back of car.....
L-R Firewall side 38"
L-R Trunk side 34"
Lto tranny mating surface 14"
tranny mating surface to R 24"
L-R strut tower tops 30"
Length:
23 1/2" + a small 1 1/2" alcove under rear window but this has pipes etc.
Height:
Frame top to fender top 24 1/2"
Tranny shaft to fender top 18 1/2"
Battery and airbox areas are 12"L x 6"W but cluttered and oddly shaped.
