The engine in the '73 has bushed lifter bores and BAM needle-bearing lifters that I bought before BAM starting offering bushing options. My backup engine block is fully machined, except the lifter bores aren't bushed. I'm wondering if I need to search out a (semi?) local shop that can bush it, or if I could continue to use BAM stuff w/o that extra bit o' work to the block.

For anyone not familiar w/ what BAM's lifter body looks like, I've attached some pics. Thx

FWIW, they have both pressure-fed bearings / bushings and pushrod oiling

I have one customer that’s run 2 drag weeks with them in a 440, and another one who’s run one drag week……… both unbushed blocks.
No issues.

My block is at the shop now for lifter bushings as the bores were worn too much. Had .0036" clearance at the worst and were not round.
Will be using the BAM bushed lifters. This is the first build I'm trying bushed versus rollers.
The pushrod oiling hole in the BAM BBM lifters is opposite of the oil galley so it relies on edge orifice oiling.
My BAM BBC lifters (.904") have the pushrod feed holes clocked differently.
Nice to know BAM configures the lifters properly for the engine brand, instead of plugging .904 Chevy parts into other brands.

We have done three in the last year that way. No issues so far. One is my 655

Mine have been in for couple seasons now with mostly street driving. Had a few full throttle freeway blasts to 120+ and just at the track where i ran 1/8 mile only. Unbushed 400 block with Bam bushed and pushrod oiling and no issues yet. Best Machine told me not to run any full throttle 1/4 mile passes without a bushed lifter bore as those lifters could cause the pan to be sucked dry. I have not run any 1/4 miles passes mainly because of his statement.

Sucking the oil pan dry probably depends on the oil pan capacity and the rocker arm type used (restricted oil flow versus non restricted and roller or bushed : work:)

Agree, but i think the point Chuck was making was a loose lifter bore with those lifters could cause an issue. My non bushed lifter bores in the 400 block are really snug, so i dont think i would ever have that issue. I did notice though that the cold oil pressure was 5psi down from using the flat tappet lifter.

Three unbushed block w/ BAM lifters builds?

Are they both using the bushing-style lifters?

DLC coated steel bushings……..which are what I’m selling the most.

I have another customer who took a road trip a couple of months ago.
Tulsa to Atlanta and back, and I’ll have to ask…….but I’m pretty sure he used those same lifters in his engine.

yes sir. One old Megas block, one World iron block and one Indy 4.84" block. They are also going in my Indy block for my 64 as well. If I ever get it done. FWIW my truck has Isky red zones in a bushed KB. We also use the DLC coated steel bushings.

I run an unbushed set of BAMs in my smallblock, I noticed my hot oil pressure is a bit lower but I restricted the rocker shaft feeds with a knurled bushing around the #2 & #4 hold down bolts (works really well) and I have a 9 qt dragster pan and an Accumulator for insurance....so no issues at all.

I like them because they were a lot shorter and lighter than the Morels I was running, which also makes the pushrod angle issue a bit "less bad"