From my notes. Tommy Nolen (real61ss) had the only documented 305 hp engine I;ve ever seen.
61 305 HP RPO 572
-RPO 575 Initially, until about Feb 61, the 305 was only available as the RPO 575 305 hp engine which had a solid lifter cam, 11:1 compression pistons and the smaller 379 heads. Suffix code GD and was only availble with the HD powerglide.
-RPO 572 The short block was the same as 250 and 380 hp engines. Suffix code GE for powerglide and FL for 4 spd.
Heads were 1147's (part #3785085) but without the stronger springs....used the same springs as the 379 heads.
HD Powerglide was the same as Corvette PG.....had welded torque converter housing instead of bolt together like regular PG. Other differences were nternal parts and governor.
Intake was cast iron and I believe the one on Tommys car was cast 3769937.
Book says carb should be AFB 3221S, but Tommy's car had a 3012S.
I believe air cleaner was single snorkel.
Distributor 110948
Coil 115083
Starter 1107891
Generator 1102173, optional 1102174, both 35 amp
-119235 V/R
--Gen pulley 3.62 "PD (pulley diameter?)
-Fan 18" diameter 5 bladed, staggered
-Not sure about balancer, but I would think it would be the same as 250 hp since the bottom end and pistons are the same.
_Pulleys I would think would be deep groove to match up with the high performance generator and pulley which is the same as 340 and 350hp.
-Standard rear axle ratio with PG was 3:55
This is all info I have derived from the documentation in the factory manuals, service bulletins, assembly manual and Tommy's car. It's the only real 305hp car I have seen.
Don't take all my word for it, do your own research as mine may well be wrong.
Cecil
61 305 HP RPO 572
-RPO 575 Initially, until about Feb 61, the 305 was only available as the RPO 575 305 hp engine which had a solid lifter cam, 11:1 compression pistons and the smaller 379 heads. Suffix code GD and was only availble with the HD powerglide.
-RPO 572 The short block was the same as 250 and 380 hp engines. Suffix code GE for powerglide and FL for 4 spd.
Heads were 1147's (part #3785085) but without the stronger springs....used the same springs as the 379 heads.
HD Powerglide was the same as Corvette PG.....had welded torque converter housing instead of bolt together like regular PG. Other differences were nternal parts and governor.
Intake was cast iron and I believe the one on Tommys car was cast 3769937.
Book says carb should be AFB 3221S, but Tommy's car had a 3012S.
I believe air cleaner was single snorkel.
Distributor 110948
Coil 115083
Starter 1107891
Generator 1102173, optional 1102174, both 35 amp
-119235 V/R
--Gen pulley 3.62 "PD (pulley diameter?)
-Fan 18" diameter 5 bladed, staggered
-Not sure about balancer, but I would think it would be the same as 250 hp since the bottom end and pistons are the same.
_Pulleys I would think would be deep groove to match up with the high performance generator and pulley which is the same as 340 and 350hp.
-Standard rear axle ratio with PG was 3:55
This is all info I have derived from the documentation in the factory manuals, service bulletins, assembly manual and Tommy's car. It's the only real 305hp car I have seen.
Don't take all my word for it, do your own research as mine may well be wrong.
Cecil