The clutch disc should be OK - it fits the "snout" on the SM-420
The pressure plate will be OK, if it matches the clutch diameter, and if the pressure plate will bolt to flywheel (correct number/size bolts).
The flywheel is OK if it attaches to the 270 crankshaft (correct number/size bolts).
It is my understanding that the number of flywheel-to-crank shaft bolts might be different for some GMC engines/years compared to Chevrolet crankshafts.
If the flywheel bolts are 7/16-20 like a Chevy 235, the torque should be 55-60 ft/lbs. I use a little blue Loctite on the threads as an extra precaution. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Ed, that is an issue I am still trying to fix. I think I can squeeze the radiator in without any modifications but the front motor mounts will have to be modified. Any suggestions? Also; any recommendations on how to lift the engine? I've been using bolts in the head that hold down the rockers.
So I have both a Chevy radiator and a GMC radiator. Are there any differences between the two as far as performance or fitment? The GMC is for the 270 and the Chevy came off a 235. The truck is a 48 Chevy 6100.
I have no clue of any difference other than dimensions which one can measure and pressure capacity, check original truck specs for that. If unknown, 5 psi is usually safe.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
So the pressure plate and flywheel I had on my 270 was an 11" with 9 mounting holes. All of the other pressure plates I have found have 6 holes. Why the difference? Should I replace it for an 11" with only 6 holes? I mailed the pressure plate to Jim Carters as a core. They junked it and cant find a replacement. What do I do now?
