4.3L Vortec Cylinder Heads problem

[brownies]

Cracked head discovered after removing engine in boat. The 4.3L had what looked like a 95 or so model reman in it with center bolt valve covers.<br /> I grabbed a pair of 02 S-10 Vortec heads and bolted them on along with a suitable carb intake manifold.<br /> Neither set of heads have adjustable rockers. Lifters are the same, pushrods same, rockers ditto.<br /> NO compression due to the valves not closing completely. Some shims cured the problem.<br />Does anybody know what is different about the blocks that can cause this? Never had this trouble installing 5.7L Vortec heads on older blocks.

 

[Bondo]

Re: 4.3L Vortec Cylinder Heads problem

Are you saying that the Lifters Bottomed Out ?????<br />Where did you Shim ????<br /><br />I know there have been Several different 4.3l blocks.......<br />Early...... Looks like a Short 350......<br />1 has..... Roller Lifters.....<br />1 has..... A Counter-Balance Shaft just above the Cam,+ Roller Lifters......<br /><br />Never Heard of Your Problem though...............

 

[brownies]

Re: 4.3L Vortec Cylinder Heads problem

Shim under each rocker stud. (.090)<br />Had a .075 that I checked one with, but, only thing I could find on a Sunday was some washers from auto zone. They were .090 and seemed to work fine.<br />The only trouble I've EVER run into, other than this was having to grind the bottom on intakes to clear that balance shaft (later long blocks with early TBI and Carb intakes). I just can't ever remember actually using a set of late "vortec" heads on an earlier roller block though. Both engines had that balance shaft also. AND, the intake bolted on without any problems that would be associated with deck height or angle.