Pete Munroe Pete think Jerry is trying to save you another failure to start with and if you are going to race alot, the aftermarket block is stronger and better
oil system is the way to go IF the pockets will allow it. Getting the motor out and have a machine shop go throught it is next. If none of the mains are spun a sonic check of the block and boring the block .004" and buying custom pistons that are .045" over size. This give you 1-2 more builds of this block. Then you have a .060" over if the block is not cracked.
Can you get oversized crankshaft bearings if the block saddles need to be bored? Is the crank OK?? How much material to clean it up? The whole bottom end will need to be rebalanced again with flywheel and dampener which brings me to another point of endurance racing, getting a custom balance with ATI for high rpm driving. The more the harmonics can be reduced in the motor the better and longer it will last on the track. This is not cheap, last motor I worked with was about $1K. Motor was smoother after this was done.
Have you looked in local junk yards, E-bay or craigs list for another iron block? It might be better to look for another block and save this one for street driving. I don't know how many years of hard abuse this block has giving you but they all have their life spans and like cats have 9 lives. I have seen major damage to cars with rebuilt motors that have been done a couple of times. Trying to save money may cost in the long run.
I think you have hit the limit of what you have in the car at this time. Custom
oil pans MAY help, scrappers are not going to hurt anything and only help
oil to get back into the oil pan. Dry sump if you keep racing is going to be needed. An accusump is a fix but again how long will this work. I didn't pull bottom bearing on motor yet and know my car pulls about 1 "G" and on long turn know that the accusump is pushing oil into the motor. I also have rolled off the throttle at this point to allow oil to return to the pan faster. You would think that 12 quarts of oil would be more than enough to keep any motor alive on the track, it's questionable. Compare rebuild against replace for block and bottom end machine work and parts. Good luck Rick L. Ps there is a 5 bolt 289 block on e-bay for $200.00 stock bore with lite rust in NJ about 1/2 hour from my house and Dyno-flo has short blocks for $1,900.00 at .030" over seasoned in NV also on e-bay. some thing to check. $500.00 with shipping? just a thought.