Originally Posted By Cab_Burge
The block in your pictures is not a 400, it is a 440 block with the last three numbers in the casting number "440", not "400". The supposidely(SP?) best 400 blocks are the cold weather)1971 castings from June of 1971 to September or October "230" castings with the really large casting numbers, the others after that are the 3614230 casting numbers used up to around 1973 or 1974. The casting numbers I have on 400 blcoks after that are either 400530-400-1 or -2 castings shruggy All Mopar blocks should have a casting date on one side like 12-9-75 or 2-16-72 scope That will tell you the day, month and year that block was cast in up All 400 BLOCKS should have all the cylinders sonic tested before boring up twocents I had a 230 casting(not sonic tested properly runaway) split a cylinder wall on the dyno, it had really bad core shift on the drivers side and wasn't saveable whiney shruggy IHTHs up


Thanks Cab,,,,you see as bad as ME scope
I said RB block,yes that is a 440,have never owned anything else...
On 440 Source they talk about a "630" late 440 that has .500 web instead of .375.Not all "630" blocks are thicker... This is one of those thicker blocks I have.
Its a "virgin" core STD. STD.STD..
If the hype it true this the "best" production 440 as far as web thickness.

70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!