How I was able to get my engine built. Hopefully this helps the next day. Took so much research to figure this out. Local shops were not of much help. The "narrow" rockers were not really narrow. Went with the LSa for vaccum for the computer.

Some of the part numbers were
Springs Engine Pro 02100116 1.250" Valve Springs.
Silver lite 1436 pistions (old style rings)
Comp Cams 5604408 260AHR12 260/266 206/210 @50 LSA112
Meling high volume oil pump
Timing set wider 73112
350 1.50 7/16" Self Aligning Stainless Steel Roller Rocker Arm Set
from AT RACING WORLD PCE261.1184 (kinda of wide)
ARP Chevy Big Block BB .496cu rocker arm stud kit 1357201
Washers for rocker arms picked up from local bolt shop (all same thickness not home depot bs).
Short poly locks

Next time id use the newer Vortec skinny rings pistions get 5hp more see video of hot mag doing that test.

To convert your older tbi to multi port try these timing covers. Slighty pricey but cheap way to keep factorty multi port system that you can get from any bone yard. That's if you don't also have camshaft retaining bolt holes for the roller camshafts.
https://www.eficonnection.com/home/ca...



I just do my best to share my information.