Rebuild engine: GMC Motorhome Digest V1 #33

[henderson]

>
> Howdy,
> Have looked at several GMCs and most have high miles on the original 455
> or 403 engines. What is the best route to take for an engine
> replacement, look for a good block and build up from there or by new??
> Also, what engine and what drive train?? And finally, is there a good
> electronic fuel injection retrofit? HELP.
> Bob

Hi Bob,
My experience was I rebuilt the 455 which was the original equipment in
our 1976 Birchaven. The engine had 112K and all spec parameters seemed
"sanitary" prior to making the decision to rebuild. Once I made the
decision to rebuild I got a second opinion from the engine shop where
the machine work would be done. I cannot emphasize strongly enough that
you must find a competent and honest shop. Since the machine shop I used
also builds racing engines, they made several recommendations regarding
cams, rings, valve guides and so on. I have been very pleased with the
outcome and would do it again.

Tom - Houston

 

[penny & bob mckinley]

>
> >
> > Howdy,
> > Have looked at several GMCs and most have high miles on the original 455
> > or 403 engines. What is the best route to take for an engine
> > replacement, look for a good block and build up from there or by new??
> > Also, what engine and what drive train?? And finally, is there a good
> > electronic fuel injection retrofit? HELP.
> > Bob
>
> Hi Bob,
> My experience was I rebuilt the 455 which was the original equipment in
> our 1976 Birchaven. The engine had 112K and all spec parameters seemed
> "sanitary" prior to making the decision to rebuild. Once I made the
> decision to rebuild I got a second opinion from the engine shop where
> the machine work would be done. I cannot emphasize strongly enough that
> you must find a competent and honest shop. Since the machine shop I used
> also builds racing engines, they made several recommendations regarding
> cams, rings, valve guides and so on. I have been very pleased with the
> outcome and would do it again.
>
> Tom - Houston
Good evening Tom,
Would be interested in some of your thought processes prior to
rebuilding. My own experience is that good competition engine builders
are the best around but rarely have time for off-the-wall projects like
ours. Anyhow, did you re-build the existing block, or start with a new
one? Did you re-build it back to stock or tweek it??
Thanks for the help
Later, Bob