Factory Stamped Rocker Arms?

I have a bunch of loose stamped rocker arms. What is a quick way to ID the small block rocker arms from the big block ones?

BB have L and R pushrod seat offsets; SB are centered, IIRC

They both have an L and an R rocker.

the number stamped on them is usually that last two of the part number but I'll be danged if I remember the numbers anymore.

SB: the OE ones have a pronounced L/R offset but I have some replacement SB ones from the dealer & the pushrod round recesses look "almost" centered (I was expecting the offset) & no numbers just a "X" on the horizontle oil deflector tab on the top side above the pushrod oil hole. Pedestal slot is a weak 7/8" long/strong 5/8" wide.

Pretty sure you are either talking about magnum rockers or speaking chevy

LA rockers don't have a slot. Or an oil deflector tab.

I assume he's talking about LA rockers because if they were magnum rockers it'd be real obvious.

You are correct brother, magnums. Too much going on upstairs! (too many projects).

3418424 and 3418425 were the mopar part numbers for small block 340 360 70-78 and later 318 maybe other years too. not sure of the stamped number Edit: one on ebay had 210RT on it if that helps. Any numbers on yours??

As are 3004716 and 3004717,

2536145 and 2536146

4095708 and 4095709

4100774 and 4100775

depending on the year. Probably a couple others too.

I had believed that the B/RB rockers were a little longer than the SB rocker arms. Can anyone confirm that there is a length difference between the two?

The ones that I have look at so far are stamped F2RT and F5LT and a few have a stamped triangle with a P in the middle.

Small block roughly 3.03"; big block 3.3".

Thanks... I was at a friend's shop yesterday who had a set of BB rocker arms and I also read 3.3" on them.

Small block rockers are 3 1/16" end to end and big block are 3 5/16" for those that just want to measure with a tape measure.