I am curious if anyone out there knows whether it is possible to take a set of small valve Ga heads and convert them to large valve Ga heads?

If yes, what would need to be done to accomplish this? I assume it would take machining work but how extensive would they need to be machined? Would it be expensive? Looking for someone who knows.

Thanks.

 

Just did it on this last iron headed build I did ("455 dyno run").

The stock G heads had mostly 30 degree seats. Depending on what cam you have you'd probably benefit by going to a 45 degree seat with the larger intakes.
Get a reputable shop to cut in the new valves and do a minor bowl blend. It will be money well spent.

 

1) buy new or at least larger valves
2) have the machine shop fit them.

It's as easy as it gets. The difference is what, 0.072" at the most... Thirty five thousandths inch cut. No worries. I had the 403 2" intakes put in the #6 heads when prepping them for my 403. You may wish to price around first, prices vary. As does workmanship. It'd be nice if they got your valve stem heights right.