Putin together 69 327 Chevy 250 hp Chevy motor together motor did run, no issues put rings & bearings, oil pump, ,I was thinking of putting 1964 202 heads on it the motor !i traded somebody parts for these heads i dint notices that they had different with springs on them the one head has 1.25 wide spring the other has wider spring so wide some one widened the spring pocket maybe 3/8 of a inch , i was think ing of taking the springs & retainers off of the 69 327 heads 185s# putting them on the 461s# ? will the springs move around some what, not having the spring pocket to lock the spring in place or do-sent mater? the 461 heads have some valve guide wobble, also the 69 springs have a steel cup that sits on top of the spring do i have to put them back on what is ther purpose other than add weight the earlier heads dint have them on them! o one more thing what kind of compression will the 461# heads change my motor being that the 461 are 58 cc& the 185# are 70 cc the motor has flat top pistons with 4 eyebrows probably was a 9.1 motor stock. thanks!!!
It'll probably ping with that much compression. The metal cup is part of the valve seal, it acts as an umbrella to keep oil away from the guide. The other part of the seal is the O ring that's on the valve stem. If you don't use the cup, then you probably need to put some other type of seal on the valve stems. In your situation, I'd leave the heads that came on the engine, they are working, and the "new" heads sound like they need work!
Squirrel is correct. they do make umbrella type valve seals if your guides are machined to fit them. However leave it alone or get later heads that are already unleaded combatable.
i'd re do the old ones that were on there the 202's sound mix (mis) matched... can not add to what Squirrel has said hes CORRECT as usual
new guides , at least exhaust (new) seats ,(on the 461's) and, it MAY be easier to OPEN up the spring pockets to match each other... there are spring cups ( usually hardened ) to use in the bottom of the spring pockets, ranging from 1.360 OD to 1.750... there's just a TON of springs out there , most common for SBC 1.44 dual good luck and let us know the outcome we lovpictures...
Are you confusing casting numbers? 461 heads have a 62 cc chamber, 416's have a 58 cc chamber, and smaller valves also. A 250 HP 327 came with Power Pack heads; using the 305, 416 heads would give you a CR boost, and possibly 1.84 intake valves, although most had 1.72 intakes. I am Butch/56sedandelivery.
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