Thanks for the advice. Yes they are #11
heads and I will go with the screw in rocker arms and I will look into changing the valve sizes. I will assemble the engine and everything else on the car I hope. Ive looked at different wheel/rpm calculators and such and Iím hoping the 14x7 rally IIís with 225/70/14 tires, 3.70 rear and 200-4r gives me good initial acceleration and a good highway gear - the acceleration left something to be desired as original. I am looking at the butler internals and to buy the book also
Sounds good. You can have the block notched by a machine shop, but I am pretty sure yours should have them. I included a photo of a 350CI block with the notches/scallops on the side of the bores. This is a 1970 block.
"All 350s can safely be bored 0.060-over. The most desirable blocks to look for were made from 1968 through early 1970. They may not have the correct mounting bosses needed for some later applications, but their larger cylinder-bore valve chamfers require less notching for valve clearance with big cams. Check for valve-to-bore contact by placing the valves, retained by clothespins, in the heads. Coat the potential bore-to-valve interference areas with machinistís dye, place the head (with no gasket) on a bare block, and carefully drop the valves to establish the contact point.
Valve To Bore Contact Is Most Likely To Occur On The Exhaust Side. Grind Clearance As Needed. Maintain 0.025 Inch Clearance Between The Bottom Of The Notch And The Top Of The Piston Ring Land At Top Dead Center."
If you go bigger valves, 2.11" & 1.77", you machinist will have to open up the "throats", which he should be able to do. You will want to gasket port match the intake side of the heads. You can do this yourself after you have the heads disassembled, magnafluxed for cracks and hot tanked. You do all this kind of work before having the valves done. I used the RA IV intake gaskets and then blended the taller roof in about 1/2". YouTube is your friend if you want to get an idea of what you are doing.
If you decide to go with 1.65 rockers, you have to elongate the pushrod holes that go through the head or they will hit. However, I would stick with the factory 1.5 ratio as it puts less side loading on the rocker arm stud. Just get a cam with the lift you want to go with using the 1.5 rockers.
If you go with larger valves, I went with the Ferrea stainless steel valves. Also went with the longer RA IV valves so there won't be any issues with a high lift cam. You will need matching springs and retainers - which you want anyway going with a roller cam. Some will suggest adding hardened valve seats on the exhaust side. I don't see a need with the SS valves, but if you go high spring pressures and you have valves pounding the seat, hardened seats may be a plus. This is something to discuss with your engine builder.
I recommend buying the Pontiac Heavy Duty Parts Specs by H-O Enterprises. Several on Ebay and inexpensive enough. Has a lot of info that may be of interest or at least give you a good bit of Pontiac engine knowledge: https://www.ebay.com/itm/PONTIAC-HEA...-/391930120552