My bet is that the 273 V8 running slightly slower rpm would match the 3.9V8 in 'brake specific fuel consumption' because of the stroke difference and piston speed friction....but compression ratio differences will dominate.
what stroke difference? the 273 is a 3.625" bore by 3.31 stroke, the 3.9 is a 3.91" bore, 3.31 stroke?
Oh, and hotroddave, it looks like the 3.9 never had ears for engine mounts, just the 3 bolt holes, even the LA version according to this site http://www.mopar1.us/sort.html but then that might be a blessing, as you could build brackets to mimic the ears out of some 3/8 or 1/2" steel and put the motor just about anywhere you want....
I still personally think the very minimal gains of the smaller displacement of a 273 will not be worth it given the cost of parts (trying to find 0 deck 273 pistons), vs building up a roller 'teen.....UNLESS you can maybe use stock low comp pistons and a longer aftermarket shivvy rod (6.25"?) to get your 0 deck....
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
