Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - 305 head on a 350 sbc
View Single Post
  #31 (permalink)  
Old 06-08-2011, 02:52 PM
cobalt327's Avatar
cobalt327 cobalt327 is offline
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 616 Times in 565 Posts
Originally Posted by 1968chevy
Would a set a 305 head work on a 350 with flat top piston stock piston the 350 came with I was just wondering and can you run pumped gas the motor has a edelbrock manifold and 600 cfm and would I get more power
You need to know the piston to deck height, the dish volume of the pistons and the combustion chamber volume.

If the pistons are the common dished 350 pistons, they're around 11cc. The piston will reside about 0.025" down the hole if the block is stock, undecked. Now the heads are usually somewhere around 58cc. That leaves the head gasket thickness as the final factor. The thinnest is about 0.015 steel shim. That gasket gives a good 0.040" quench and a CR of 10.4:1. Using a common 0.041" composite gasket gives you a 9.75:1 CR w/a wide quench of 0.066".

To use those heads the right way, they'd need to be ported and the pistons should be reverse dome, D-shaped dished pistons w/a dish volume of about 22cc and a 0.041" quench to give you a 9.2:1 CR- which is the max I personally would try to run w/iron heads and today's gasoline.
Reply With Quote