Block casting 3837004 was used in 1955-57.
Truck had solid lifters,
Passenger had both, solid or hydraulic lifters.
I would not assume that the push rods that came out are the same size you put back in.
Are you sure your block is a 56, because 55 w/ solids, uses the smaller push rod. And if I'm reading this right all 56-57 use the longer push rod. I have the longer one in my 56, 3837004 block.
According to the 1929-57 Chevrolet Master parts catalog:
40-53 ALL w/216 ...... 10 7/16 long
41-55 ALL 6 cyl. (exc. 216, P.G.),
53-55 CORV. 6 cyl...... 10 3/4 long. FLAPS listing is 10.819" O.A.L. Part # RP3018. Priced as low as $2.20ea.
50-52 PASS. w/P.G. .... 11 1/4 long
53-55 PASS. 6 cyl. w/P.G.,
56-57 ALL 6 cyl..... 11 13/32 long. FLAPS listing is 11.474" O.A.L. Part # RP3020. Priced as low as $2.04ea.
