Have you swapped a 350 for a 454? Advice needed

GMFORLIFE

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Cleveland Ohio
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Dennis
Truck Year
1973
Truck Model
C20 Camper Special
Engine Size
454
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Yes you can use the 350 mounts. But if there is a plate between the mount on the block, use that too! This is needed for proper spacing with the frame mounts.

I leave the transmission in place.

I converted over to the factory shroud


Nothing looks prettier than an orange BIG block engine compartment...sweet!
 

sirweesarunch

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Oceanside
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John
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1980
Truck Model
K30
Engine Size
454
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It was my experience with the 6.2 that no way was all that coming out and going back together connected together. In my case the tranny had the Transfer case adapter connected , the truck is lifted 4” . My fenders and hood were off and I still had trouble getting the motor high enough to tip it in , no tranny mind you. So in order of mounting I set the motor, lifted the tranny from below and then lastly added the np 205 …. I would guess the whole thing is right arouns 1500 lbs in weight.


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RecklessWOT

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1987
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V10 Suburban Silverado
Engine Size
350 TBI
I am confused by the Santa with the flag pole...


https://knowyourmeme.com/memes/o-rly

Seriously?
I'm not much of an internet guy, I don't have a smartphone or a facebook or any of that ****. But honestly you really don't understand ORLY? That is like one of the oldest memes in the world probably only second to the hampster dance and that hideous 3D dancing baby. It's gotta be from like 20 years ago, no joke. And those two were stupid E-Mail chain mail things, ORLY was the only thing I remember that was posted in response to what other people said like a modern day meme, it honestly was probably the first...
If you have used the internet at all since it was created you should be familiar with it by now, even a techonophobe hermit like myself gets the freakin reference lol...

If you had a heartbeat 20 years ago, you should realize it's basically a sarcastic way to say "Oh really, is that so???"
 

AKguy

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Okay, so I am 64, had somewhat of a heartbeat 20 years ago and had no friggin clue regarding “ORLY”. I really need to spend less time with the family, the dogs, and making stuff in the shop so I can have a more meaningful, informed life!
 

Customblue

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489
I must not be as hip as you hoss. But to answer you, thus was the case when I dropped my 489 in my truck. Plugged the waterpump off and at an idle it ran 20 degrees hotter then with the bypass hose installed.
 

dsteelejr

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Hudson, WY
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David
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1973, 1980
Truck Model
Cheyenne super C20 camper special, Sierra K25
Engine Size
350, 454
Can someone please shoot me a pic their whose routing off the water pump? Want to make sure I don't mess up the cooling flow.

The 1979 service manual says:

Heater hoses are routed from the thermostat housing or inlet manifold and water pump (radiator on some automatic transmission vehicles) to the core inlet and outlet pipes as shown in Figure 1A-9. Hoses are attached at each end with screw type clamps.

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From the factory on trucks with manual transmissions the heater hoses attached at the water pump and intake manifold. On automatics the return hose went to the radiator instead of the engine. Not sure why this is or what difference it makes, but I'm sure the designers had their reasons.

Also, the 1980 service manual mentions while removing and installing the water pump:

"On 7.4 liter engine, remove by-pass hose."

"If installing new water pump, transfer heater hose fitting from old unit. On 7.4 liter engine, also transfer bypass fitting."

"Attach lower radiator hose and heater hose to water pump. On 7.4 liter engine, install by-pass hose."

From the factory it looks like the 454 had the bypass. However, my 80 K25 had a factory 350 and PO swapped with a 454. I dropped a reman 454 in it last year and I hooked up the bypass and had barely any hot coolant flowing to the heater core and had next to no heat in the cab during winter. I ended up deleting the bypass and now I have heat since the coolant is now forced to go through the heater core.
 

Craig Nedrow

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Washington State
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Craig
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1973 (have two)
Truck Model
K10 and k20
Engine Size
350, 454
https://www.gmsquarebody.com/threads/1973-k20-350-to-454-swap.29840/
Start with Post 6. Everything fit EXCEPT the 350 mechanical fuel pump, fit, but has a shorter arm, and did not have enough pressure or volume. Replace with a BB fuel pump and all good. Stock radiator, shroud, motor mounts, drivelines, everything fit. You can leave in the 465, but will need help lining up the throwout bearing, yes pulling the trans and transfer is a PETA.

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Marc Rexroad

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Northeast Nebraska
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Marc
Truck Year
1979
Truck Model
C30
Engine Size
350

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