lets not start another myth. the late model GMC motorhome 455 heads were the
worst they ever put on the 455. they were called the smogger heads. Caddy
heads are fine heads.
>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,
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
worst they ever put on the 455. they were called the smogger heads. Caddy
heads are fine heads.
>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,
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
