Alright I got my 305 decked and bored .030 over and I was at this swap meet awhile back and picked up some 350 heads that were all redone with new valves and springs for $100. I thought it was a good deal so I put em on my 305 once it was done at the shop. Now that the car is running and driveable I'm wondering if there would be a noticeable difference in power if I took my 416 casting 305 heads to the shop and got them redone and put back on.

Thanks,
Joe

 

Id be careful running those heads, normally 350 heads on a 305 with have valve/deck or cylinder wall interferance issues.

 

I've driven it about 300 miles and haven't had any problems like that. Only problem is my carb hesitates and I don't think that has anything to do with the heads.

 

The most common 350-heads-on-a-305 problems are:

1) Larger chambers reduce compression and therefore power (may even cause carb hesitation...).

2) "Rebuilt $100 350 heads" are really huge chamber, small port, can't flow if their life depended upon it smog-era 882's. If you like $100 paperweights, you got 'em.

Fix up your 416's and get them back on there.

 

I think I will get em back on there. Any idea how much it would cost me to have the machine shop go through them for me?? I'm also thinking about porting them myself.

 

That would be a good idea. Have the heads cleaned and Mag-checked for cracks. If the cores are good, port them. You can have the shop machine the seats for larger valves (1.94" will fit with some massaging of the chambers, or 1.875" Olds valves will fit if you machine the spring pockets), and have the valve bowls enlarged, or simply enlarge the bowls for the stock 1.84" valves. Then you can port to your heart's content. These templates might help guide you:



Plan on screwed rtocker studs and decent valve springs. Of course, that will include dumping the exhaust valve rotators no matter what. Once you're satisfied with your port work, clean up the heads as best you can, then assemble.

You'll have much better luck with decent '416 heads: