Topic: 1971 455 HO Block

[2ndchildhood]

I know this is supposed to be for cars but I just ran accross this block that I might be able to buy.  It's a 455 block and pistons and that's it.  No heads, no intake no crank.  There are no ridges on the cylinders.   The casting number is 485428.  That says Late 71 HO 455.  It also has SRxxxxx on the other side.  Think that might be just the vin though.  Any ideas on what I should offer. The seller has no idea what it is.

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[TAKID455]

may not be an HO block.

from another source
The casting code for early 71 455-H.O. blocks is 483677. The casting code for late 71-72 455-H.O. blocks is 485428. The casting code was also 485428 for the 455's (non-SD) for both 73+74. The block codes for the H.O. blocks are WL, WC, YE, WM, YB, and WD.

Pontiac must have used some of the same 455 blocks with 4 bolt main caps installed (not just drilled for 4 bolt caps) in the non-H.O. cars and just topped them with cast iron intakes and D-port heads. For 75+76 the 455 casting number was 500813, and as you know, 76 was the final production year for the 455.

[2ndchildhood]

I'll get back over there on the weekend and see what other codes are there.  Thanks for the info!!!

[2ndchildhood]

Anyone have any ideas what the HO block is worth and what the value would be if it was a standard 74 block?  I don't want to make a third trip.  If I go back a third time they might figure something is up and raise the price.

[logikfive]

I paid $300 for a running shortblock 455 with those casting numbers about 2 months ago.

[TAKID455]

good block 3-600 depending on condition, ect.

I do have a use for an early 71 HO block...