The eclipse engine should fit in the bay with some tweeking. I don't think it just pops right in. As far as performance things other than that, HVe in Australia now has slotted and cross drilled rotors for the Excel and Shark Racing has a strut bar for the excel. I have a strut bar on my excel and feel it increases the handling.
Timothy Zacher
1991 Excel Evo II Rally Project
#346 N
Des Moines, WA
http://www.geocities.com/nwhec/
Timothy Zacher
1991 Excel Evo II Rally Project
#346 N
Des Moines, WA
http://www.geocities.com/nwhec/