I'm going to be starting the build on my 70 440.It's a stock rebuild but I have a question about which main bearings to use.I have a set of NOS mains which are 1/2 groove and I have a set of Clevites that are full groove.Which ones would be the best to use? I understand the full oiling verses 1/2 oiling to the rods but is full oiling necessary on a street motor.Thanks,John..

Chrysler built over 750,000 440's and who knows how many 413's. How many had full groove oiling?

That pretty much answers the question for a street motor.

Full groove were designed to use for a race engine seeing a lot of track time. If your car is mainly a street car use the half groove, you'll have better oil pressure, especially if you're running hydraulic lifters.

The groove in the bottom bearing shell reduces the bearing surface that takes the most pounding.

Are they the wide groove Hemi bearings or the narrow groove truck bearings?
I like and us ethe narrow groove bearings on all my BB builds, I've seen way too many street engines,361,383,413 and 426 street wedges, spin rod bearing due to not oiling the rod bearings all the time

i'd use a sealed power 4924 main set.

That part number is for RB motors with the single groove in the upper bearing only not full groove for not RB motors
The part number for the narrow full groove RB set was SLP 4095M at Summit racing but they discontinue them last year
I j looked just (2 minutes ago) now on Summit sight and see they show them available again on special order
I think I will order some now

The full groove main bearing set I have is Clevite MS-2324P

the number i gave was for a stock replacement, which i use, and the OP said he was building a stock engine.the 4924 isfor a stock engine with stock bearing clearances , the 4095 is the old truck narrow full groove tri-metal with extra clearance. find a bearing catalog if that confesses you. i stand 100% behind my recommendation for a stock build!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!