#5 heads or #7 heads

[Junebugs 86Cuttleya]

For what engine

1969 350 olds, i have a mild cam springs lifters & rockers. Looking to port the heads looking at the #5's, I know they are the earliest. I have a new high flow oil pump. Im a weekend warrior. Had that thing surrounding pretty good if I don't say so

For what engine

Either head is decent as said. Is it a 2 or 4 bbl 69 350? Basically one is a 6cc vs a 14cc dish piston. Are you sure it is a 69 350? A 69 350 would have #5 heads, not #7 heads, read the Vin stamp pad under the driver's side head. I think the 7 heads have uneven spring pockets due to valve rotators on the exhaust side. Use W31 valves and get a bowl hog to start on whichever heads look best. The #7 spring pads can be cut. Make sure it isn't actually a 71 350 or you will need new pistons to replace the the factory 24cc big dish compression killers. Mahle makes a nice hone to fit 4.065" 10cc forged piston with a 1mm ring pack. Good luck.

I have 2 motors the first has #5 heads the 2nd #7. 4 barrel carb. Elderbroc high rise intake I'm researching the pistons now as well thanks for the info the ones you mentioned sound good. Thank you.

 

[L92 OLDS]

I'm researching the pistons now as well thanks for the info the ones you mentioned sound good. Thank you.

If you’re buying new pistons then you can set the motor up for aluminum heads with a larger chamber

 

[Kelvin's80442]

If you are going to port and polish heads, won't make much difference

 

[1320John$$$]

Stan Weiss Page has lots of flow numbers on production Olds heads and some aftermarket

 

[olds307 and 403]

Either of the heads with just a bowl hog cut, a good valve job and W31 valves should flow in the 210/170 cfm range. Procomp heads flow 225/180 out of box, minor work gains quite a bit. Edelbrock heads flow 268/190 I believe out of box but there may be a wait for them. Another hone to fit piston on a low wear block is the 4.065" 1.3cc dish with 1.5mm ring packs CP forged pistons. Mark Remmel(Cutlassefi) worked with Mahle on the 10cc dish pistons, available in a bunch of oversizes. Bill Travato(BTR) worked with CP to bring some Olds pistons to the market.

 

[Junebugs 86Cuttleya]

If you are going to port and polish heads, won't make much difference

Just porting but yeah I'm locked I on the #5's

 

[Junebugs 86Cuttleya]

Both castings are among the best SBO heads. The #5’s supposedly flow best in stock form. I had a set on my 403 and they worked well. I invested well over $1200 in the heads alone. In retrospect I would’ve bought aftermarket aluminum heads. They flow much better and you can run a higher compression ratio

Higher CR on pump gas?

 

[Junebugs 86Cuttleya]

If you’re buying new pistons then you can set the motor up for aluminum heads with a larger chamber

I know... since I've been researching I've noticed. Now I'm considering pistons that can withstand a boost of some sort... smh trying to get a great plan together

 

[olds307 and 403]

If you are considering boost, seriously consider the new Scat connecting rod, a direct replacement for the Olds 260 through 403. I believe Mark Remmel also helped bring this rod to the market as well. The factory forged rods are very soft, not great. Make sure you go big enough on the cam if you are pushing higher compression. It depends what octane you have readily available. The best we have locally is 91 non Ethanol premium. The Mahle pistons will give low to mid 9's for compression, about perfect.

 

[Kelvin's80442]

Yeah any engine builds, talk with Mark. He knows the olds. Help me build my sbo.
As for heads, I used #8's. Port and polish them and put 2 inch valves. Zeroed the deck and flat tops, have just under 9.5 to 1 compression