Building a 350 olds and it's been an awesome learning experience so far. I realized I didn't have the depth of education I wanted so I am continuing to educate myself. Books and some CO members mostly. I picked up an olds building book from "SA" yesterday and if anybody has any books they can recommend that'd be great.

Anyway, in reading about heads (I have 1970 #6s) I read this excerpt?

"If you want a free port job on your small-block Olds heads, put the die grinder down. Get big-block heads, mill the deck surface so you can get the combustion chamber volume, and presto! you have a ported head."

- if that is true then why is everybody working their SB heads, what am I missing here?

 

All 1964-1990 Olds V8 engines have the same architecture, so all heads (BBO and SBO) bolt to all blocks (yeah, allowing for head bolt diameter differences from 1976 to 1977). The problems with the BBO heads on an SBO are 1) the larger chambers with resulting drop in CR - you need to either use flattop pistons and/or mill the heads, and 2) the port mismatch on SBO intakes that causes a flow disruption. If you don't port the intake to match, you can lose any benefits due to turbulent flow. Only certain intakes have sufficient meat at the tops of the ports to allow this port matching. The Performer RPM is one of them.

Finally, it isn't clear that an otherwise stock or mildly modified 350 can use those ports. Keep in mind that as easy as this is to do, the factory did not use BBO heads on the W-31s (they DID use BBO valves in the SBO heads, however). If you are building a modified high-RPM 350, with all other parts selected to match, the BBO heads may be a better choice (or aftermarket aluminum, even better).

Now, if you are talking about an SBO 403 (which is obviously no different from a BBO 400), the answer may be different.

 

I am in the process of building a mild 350. The core motor came with a performer RPM and I wasn't planning on touching the heads (aside from replacement of stock pieces). Another member on here and I have been in contact and he is doing extensive head work as he wants to hit 350hp. I'm going probe -3cc pistons, comp xe 268 , aforementioned intake, Slayer 750, headers to 2.25 system, HEI and maybe a MSD 6al (have no researched that in any way). With the rest of the 83 H/O drive train and i'm anticipating a stout driver that runs on pump (probes + .040 gasket + .020 in the hole) = 9.501 CR. I can't figure out why I would modify the #6 heads when there is an aftermarket available and according to Bill Trovato's book the Edelbrock Performer RPM heads are a factory style replacement with a quality of "near 100 perecent perfect." If stock appearance is of no concern to me at all why mess with the factory heads?