whats the best way to go for a RB 4.15 crank that is under $1500? shooting for the 750-ish hp range.

I have yet to hear anything bad about Monlar stuff....I have no personal experience with any of their stuff though.

Molnar has them in four flavors. 8/6 bolt and 2.2/2.375 pin. I'd highly recommend the 2.200 pin if you're buying rods at the same time. No good reason to use the extra heavy Mopar rods. I also don't think there is any reason to use an 8 bolt flange at 750 hp but sometimes you have to do what you have to do.

On my second Molnar crank and rods. 1st was a 3.91 with chevy journals and 6.7 rods B block.. Second is RB 4.5 with 7.1 rods. Machine work was spot on on both. Also the Molnar rods came standard with ARP 2000 bolts.

Molnar crank and rods in mine. Toms great to deal with. Reasonable price. Spot on machining. Never dynoed mine but Wallace says 908 hp.
Doug

I wouldn't hesitate for a second to use Molnar's products.

I have an RB 4.15 2.375 Eagle crank from around 2006-07 still in a box on the shelf, how would it compare?

As the owner of 2 Eagle cranks, I'd say yours should be checked for taper in the crank & rod journals and whether the snout where the damper fits is undersized.

Call 440 Source and see how much their cranks are now
Why are you choosing that stroke instead of 4.250 stroke with the 2.200 rod journal sizes?

I'm a huge fan of Molnar. Tom AND his parts.

I've beat the crap out of his rods and crank and no issues.

How's the Quality Control on 440 Source cranks these days? It wasn't very good to start with, IIRC.

Not answering for the OP, but just an observation that a 4.15" x 2.20" combination could be a no-grind & drop-in deal.

The 4.250 stroke 2.20 rod combo required no grinding in my RB block. I wouldn't bother with a 4.15 crank when you can get the 4.25 cranks for the same money and most likely not have any grinding to do. For the brand I have used 440 source, Molnar and Eagle and I have had no issues with any of them. Make sure you check them or have them checked by a machinist. I would buy who ever has the best price.

Ohio Crankshaft. Birdtracker

Another company with a history of crankshaft QC issues.

I bought a 4.25 crank from them. It was extremely spot on. Birdtracker

My
I would have the indexing checked on any crank that came over on the slow boat.

Good to hear. There's been a lot of bad-mouthing of OC's products on SpeedTalk over the years that left me w/ the concern that their cranks can be seriously hit-or-miss on machining accuracy.

I've use 8 or more Ohio BB Mopar stroker cranks with no issues other than one got damaged in shipping