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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: chronos on February 12, 2010, 08:52:48 am

Title: question about heads
Post by: chronos on February 12, 2010, 08:52:48 am
Don't know alot about this so throwing it out there:
Can double hump heads  with 1.6 roller tip rockers 2.02/1.6 valves
work on a 305 block or is that crazy??....lol
Title: Re: question about heads
Post by: VileZambonie on February 12, 2010, 01:28:56 pm
Not sure what you'd really gain as you'd drop the compression ratio drastically. Your 2.02 heads probably have a 72cc combustion chamber where your 305 probably has a 58cc. Could you do it, yes but is it worth the time and $ is the question
Title: Re: question about heads
Post by: HAULIN IT on February 12, 2010, 05:03:27 pm
The "double hump" heads, either bolt holes or no bolt holes (for accessories) were 64cc chambers, so yes...your going the wrong way on compression. Your main concern should be the big intake valve & small bore size, not sure if this can work or not (I'm guessing not). Even if they phisically fit without problems, the benefit would most likely be nil. The big valves & higher lift (1.6 rockers) are for something taking in large amounts of air @ higher RPM's...the 305 isn't going to want to do either. Nothing wrong with a 305 for daily use, just don't throw higher RPM "speed" parts on it & expect miracles. Lorne
Title: Re: question about heads
Post by: Josh454 on February 12, 2010, 05:37:38 pm

You may encounter interference with the valves and bore with a higer lift too.
Title: Re: question about heads
Post by: VileZambonie on February 12, 2010, 11:05:40 pm
The "double hump" heads, either bolt holes or no bolt holes (for accessories) were 64cc chambers

They weren't all 64cc's. I have two that are 72cc camel humps
Title: Re: question about heads
Post by: HAULIN IT on February 13, 2010, 11:41:16 pm
They weren't all 64cc's. I have two that are 72cc camel humps
Do you happen to have the casting numbers handy...never seen/heard of such. Lorne
Title: Re: question about heads
Post by: VileZambonie on February 14, 2010, 12:25:22 am
I can look at the casting # Monday when I'm back at work. Positive 72cc chambers I checked em myself.