58 Part interchange help

[Bob E.]

I just discovered my 739 short block is missing the rear main bearing cap. Can anyone tell me what years I can use, IF I can find one.

[Joe L.]

Re: 58 Part interchange help

Bob-----


Any rear cap from a 1955-58 small block will work. The cap may be identified by the casting number 3704108 or 3743949. You might check with a local automotive machine shop. They often save caps from scrap blocks.

[Bob E.]

Re: 58 Part interchange help

Thanks Joe, appreciate the help.

[Mike M.]

Re: 58 Part interchange help

i've got one i'll give ya. send me yer snail mail address and i'll get it out monday.mike

[Gary C.]

Re: 58 Part interchange help

Need to be careful as bearing caps were supposedly matched to a block. If it's apart might want to have machine shop check for line bore. If crank's in car, check with plastic guage to verify proper clearance values. Gary....

[Joe L.]

Re: 58 Part interchange help

Need to be careful as bearing caps were supposedly matched to a block. If it's apart might want to have machine shop check for line bore. If crank's in car, check with plastic guage to verify proper clearance values. Gary....

Gary-----

Absolutely. One can NEVER exchange or replace ANY bearing cap on any block without having a competent machine shop check the alignment of the main bearing bores. In almost all cases, an align hone or align bore will be necessary. In some instances, a particular previously used cap might not even be usable with a recipient block. SERVICE main bearing caps, when they were available for this application, were supplied in "unfinished" form so that there was enough "meat" available to fit them to any block. Used caps have already been fitted to their original block and may not have enough "meat" available to be fitted to another block.

[Mike M.]

Re: 58 Part interchange help

Gary-----

Absolutely. One can NEVER exchange or replace ANY bearing cap on any block without having a competent machine shop check the alignment of the main bearing bores. In almost all cases, an align hone or align bore will be necessary. In some instances, a particular previously used cap might not even be usable with a recipient block. SERVICE main bearing caps, when they were available for this application, were supplied in "unfinished" form so that there was enough "meat" available to fit them to any block. Used caps have already been fitted to their original block and may not have enough "meat" available to be fitted to another block.

joe is right on. even if there isn't enough meat on a donor cap off a donor block, the donor cap can be cast welded then fitted to the recipient block. most good machine shops can handle the necessary machining to interchange caps.mike