I overlooked changing the TO: header address when I responded to Chuck last
night and here is what I said in response to his e-mail:
From: Bartz, Paul
Sent: Monday, June 21, 1999 10:03 PM
To: 'CAD3M '
Subject: RE: Engine Replacement
Chuck:
Don't know where you're located, but it would be good for you to talk to an
owner who already has the Cadallac engine installed and get their opinion.
I know of one such individual who lives in NC.
As far as I know, Fritz Slama in Wisconsin pioneered the conversion.
I assume you know that you have to relocate the alternator and air
conditioner compressor?
I'm also told that the 455 cid heads will flow more air vs. the Cadillac.
However, I believe that that is @ far more rpm's than we would ever see in
our coach operation.
I'll also add I've heard that other than from salvage yard sources, because
of the lack of popularity of the engine, there are starting to be parts
availability problems with the Caddy engine at this stage of the game. This
will only become more pronounced in the future. Not as critical yet for the
403/455 engine.
Paul Bartz
From: Patrick Flowers [mailto
atri63]
Sent: Tuesday, June 22, 1999 3:18 PM
Subject: Re: GMC: Engine Replacement
Looks like no one else has tackled this one, so I'll wade into the fray,
>The engine is a 403 with 106,000 that I will replace this winter with a
rebuilt engine.
I'll second the advice you've already been given. Unless your 403 is truly
sick, don't replace it. There's much you can do to help these motors(fix
vacuum leaks, frozen advance weights, wire core plug wires, valve job...)
without resorting to a transplant.
> ...why the 500 Cadillac is not the engine of choice when engines are
swapped or replaced.
Well, IMO the Olds engines are capable of developing all the horsepower that
the rest of the GMC drive system is capable of delivering to the ground. In
addition, they're pretty well supported by the aftermarket parts system.
> It appears to have better heads from a flow standpoint
I've heard this before, but never can seem to get it documented. Can you
cite a reference where you found this?(not being argumentative, but IMO this
is a persistent myth) According to Mondello, the Caddy is asthmatic
compared to the 455. The real restriction in both engines is the intake due
to the height restriction of the installation. If you can live with a
raised engine cover, go with an aftermarket intake for better breathing.
Also, while pricey, there's always the Edelbrock aluminum heads.
> beefier crank
Never heard of crank problems on the Olds engines
> some say better oil management
Recently plowed ground - not an issue in our RPM range.
> the obvious larger capcity translating into more torque when properly
tuned.
Again, unless you're into "burnout" contests, any additional torque is not
useable.
> It looks like it should be the engine of choice. Why isn't it?
IMO, the swap is way too difficult for the benefits (questionable) that are
realized. Clarence Buskirk played with both the Caddy and big-block Chevy
engines, but AFAIK, Buskirk-Rush still does not offer a "turn-key" package
engine swap - just a "teaser" engine mounted to a bare chasis in their
showroom. They'll do it on a "by the hour" basis - if anyone else knows
differently, please clue me in. IMO, if there were any really viable engine
swaps, one of the big GMC shops would have a turn-key
package.
> Are their installation problems that make this a non-viable swap?
Any engine swap is difficult with a myriad of little details to be attended
to. The most obvious problem is properly shrouding the cooling fan. If you
can't use the Caddy accessory mounting brackets due to height restrictions,
then it becomes incredibly complex. For my money, I'll stick with the 455,
since that's what is in my coach, but the 403 is a fine engine too.
Once again, IMO, the Caddy is too little "real" bang for the buck,
