The 041 were very late 60s, early 70s truck and large car 350 CID. Essentially were double humps internally, but with bigger 68 - 72 CC chamber. I'm not aware any came with 1.94 or bigger. These were basically double humps, but with low compression chamber and small valves. The good is they were pre EGR, production ended 1973 IIRC. Fairly stout, and fairly standard on Chevy/GMC 350 4 bolt main 4x4 pickup.
1973 and after was the 462624 was the 1973 large 76 CC replacement for 1973, but have been told some were in 1972 and some on Nova with the 307. Light casting, very crack prone, always 1.5 exhaust, but intakes could be 1.72, 1.84, 1.94. Intake runner 161 CC and exhaust 62 CC. They will accept 2.02 - 2.05 & 1.6, and history is can be ported for good flow. I had a set 1.94/1.5 gave to guy building older Chevy truck, just wanted noise and smoke for car shows, no intent to race.
The 3884520 power pack had two types from factory. One was 1.84/1.5 64 CC from the 250HP 327, which is the one I have, ...I think 1967 variety. Might give to corvette museum. The other is 3884520 (same number), but the 283 220HP variety, 60 CC, 1.72/1.50. IIRC these were the ones that David Vizard talks about, 1.94 Intake, 1.60 exhaust. These heads have short runner high velocity, excellent for small cube SBC.
The 520s you have, I'll send some cash, the 327 is naked and I have been looking for a set of 520s. I have the October 1954 cast date all original 265 V8 Corvette, that some time near future will go to Corvette Museum, the 327 can go as well, just couldn't find heads for it.
So any way, the 520 on a 305 would be ok but better with 1.94/1.60 valves and smaller chamber. Small runner high velocity should make it spunky to maybe 3500, after that it will start running out of juice.
The 416/601 variety 305 HO heads do good on street so long as no plan to run hard and long at high RPM. Although they were used for racing, Enduro, outlaw and sprint. I've used several times for 350 high compression mainly show truck & car. It allows much more duration on the 350, bleeds off some excess compression that reduces detonation. Keeps the Dynamic around 7.6. gives good aggressive sound on street and show.
Corrections to the HO head is 1.94/1.60 and slight porting and matching.
The best overall Factory Produced 305 head is the 305 Vortec, after that you need to look at after market.
Here recently I started up conversation with aftermarket for an as-cast 305, straight or angled, small CC 58 - 64, 185 - 195 runner, 1.94 & 1.6 or 1.65 exhaust. The issue with Small Block Chevy is scavenging. But 2.02 and 2.05 intakes seem to sell better than reality.
1973 and after was the 462624 was the 1973 large 76 CC replacement for 1973, but have been told some were in 1972 and some on Nova with the 307. Light casting, very crack prone, always 1.5 exhaust, but intakes could be 1.72, 1.84, 1.94. Intake runner 161 CC and exhaust 62 CC. They will accept 2.02 - 2.05 & 1.6, and history is can be ported for good flow. I had a set 1.94/1.5 gave to guy building older Chevy truck, just wanted noise and smoke for car shows, no intent to race.
The 3884520 power pack had two types from factory. One was 1.84/1.5 64 CC from the 250HP 327, which is the one I have, ...I think 1967 variety. Might give to corvette museum. The other is 3884520 (same number), but the 283 220HP variety, 60 CC, 1.72/1.50. IIRC these were the ones that David Vizard talks about, 1.94 Intake, 1.60 exhaust. These heads have short runner high velocity, excellent for small cube SBC.
The 520s you have, I'll send some cash, the 327 is naked and I have been looking for a set of 520s. I have the October 1954 cast date all original 265 V8 Corvette, that some time near future will go to Corvette Museum, the 327 can go as well, just couldn't find heads for it.
So any way, the 520 on a 305 would be ok but better with 1.94/1.60 valves and smaller chamber. Small runner high velocity should make it spunky to maybe 3500, after that it will start running out of juice.
The 416/601 variety 305 HO heads do good on street so long as no plan to run hard and long at high RPM. Although they were used for racing, Enduro, outlaw and sprint. I've used several times for 350 high compression mainly show truck & car. It allows much more duration on the 350, bleeds off some excess compression that reduces detonation. Keeps the Dynamic around 7.6. gives good aggressive sound on street and show.
Corrections to the HO head is 1.94/1.60 and slight porting and matching.
The best overall Factory Produced 305 head is the 305 Vortec, after that you need to look at after market.
Here recently I started up conversation with aftermarket for an as-cast 305, straight or angled, small CC 58 - 64, 185 - 195 runner, 1.94 & 1.6 or 1.65 exhaust. The issue with Small Block Chevy is scavenging. But 2.02 and 2.05 intakes seem to sell better than reality.
