The motor my friend used was a bolt in. Here are some post-'69 Chryslers that have interchangeable motors. Original part numbers were (among others) 2802787 (L) and 2802788 (R):
1976-'80 Aspen, Volare four-door
1970-'74 Challenger, Satellite, Road Runner, Charger and 'Cuda
1971-'74 Coronet; '75 Coronet four-door models
1977-'81 Diplomat, LeBaron four-door models
1969-'73 Polara, Imperial, 300, New Yorker, Newport, Fury, Monaco
1977-'78 Monaco; 1979-'81 St. Regis
1980-'87 Dodge pickup, Ramcharger, Van, Plymouth Trailduster
1983-'88 Fifth Avenue; 1984-'88 LeBaron four-door models
1979-'82 New Yorker
1975-'78 Fury four-door models; 1980-'88 Gran Fury
1987-'88 Sundance two-door
Doug