I understand that in 1966 the skylark GS was offered with 2 different engine options: MT Code MR Code I believe the MT code motor was rated at 325 HP and 445 TQ. I believe the MR code motor was rated at 340 HP and 445 TQ. Can someone tell me what specifically was done to the MR motor to produce the additional HP? Also, can someone give me an estimate of what the HP/TQ gain would be for an MR code if the stock single 4 barrel carb was replaced with a duel 4 barrel carb setup? Thanks, Kurt
hi kurt. i believe the difference was the the 340hp motor used a rochester quadrajet instad of the carter afb. i think the horsepower would be about 360. some of the other guys maybe can back this up. dave
Thanks Dave. I was wondering if maybe part of the 15hp gain was from running a different CAM - higher capacity carb makes sense too.
According to a 1966 Buick Service Information bulletin, there were three 401 engines available in the '66 Skylark GS: MR code... standard 325 hp MU code... optional 340 hp with Q-jet, different cam, and dual quad- spec distributor. MS code... 11.0 to 1 compression ratio. HP was 'unestablished' The MT, and MY (low compression) were available in the large Buicks... As for the hp gain from a stock dual quad setup....I've read reports of 10 to 15 hp.
