Motor swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

01-24-2020, 11:29 PM

I’m going to post up the progress of the engine swap in my 72 C20. It might not be exciting but it will be cool to look back on.

Started with a tired, stock 350. After getting it out, I sprayed the engine compartment with EZ OFF and power washed it.

01-24-2020, 11:36 PM

Hit it with Satin Rustoleum

01-25-2020, 12:11 AM

Newness

01-25-2020, 12:16 AM

Blueprint Engines 365/405

HeavyHauler · 01-25-2020, 12:40 AM

That is going to look good! Did you get a good deal on the engine? Too bad they dont sell big blocks like that.

01-25-2020, 01:31 AM

Quote:

Originally Posted by HeavyHauler

That is going to look good! Did you get a good deal on the engine? Too bad they dont sell big blocks like that.

They are priced fairly. It showed up quickly. I’m happy so far.

**Ironangel** · 01-25-2020, 12:46 PM

Love those "Ochre" paint jobs! L-31 motor is a good choice, looks good!

**HO455** · 01-25-2020, 01:30 PM

Nice job on the prep work! That's the hardest part.

01-25-2020, 01:45 PM

Quote:

Originally Posted by Ironangel

Love those "Ochre" paint jobs! L-31 motor is a good choice, looks good!

This one is actually “dark yellow”.

ltdmstr · 01-25-2020, 05:18 PM

Holley 6210 spread bore is a great carb for those motors.

01-25-2020, 09:29 PM

Quote:

Originally Posted by ltdmstr

Holley 6210 spread bore is a great carb for those motors.

It came as a turn-key crate motor. It dyno’d at 382/419. The power is good. I would hope the drivability is good too.

01-25-2020, 11:24 PM

More progress today. I fixed a leak at the shifter shaft and changed the transmission filter today. I also installed a 2500 stall converter.

External · 01-26-2020, 02:56 AM

Sub'd for the update on driving!

01-26-2020, 01:30 PM

New trans cooler lines this morning and getting the motor out of the crate.

Daron65 · 01-26-2020, 01:36 PM

I really enjoy this thread. Im excited about how it will drive. The blueprint 355 i put in my 71 is a great engine. Sounds great, and great fun to drive. Im sure you will be more than happy with it.

geezer#99 · 02-01-2020, 07:06 PM

Before you put coolant in it, your heater hose is on wrong.
Supposed to be intake to bottom of heater core, top of core back to water pump or rad.
Yours needs to go back to rad as you need that port on the water pump for the coolant bypass from the intake.

02-01-2020, 07:19 PM

Quote:

Originally Posted by geezer#99

Before you put coolant in it, your heater hose is on wrong.
Supposed to be intake to bottom of heater core, top of core back to water pump or rad.
Yours needs to go back to rad as you need that port on the water pump for the coolant bypass from the intake.

Thank you for bringing that up. I was looking at photos of my old motor and scratching my head on that. Should I move that fitting from the pump to the intake and plug the pump?
Here is the old motor.

geezer#99 · 02-01-2020, 07:45 PM

That would work.

**clay68c10** · 02-01-2020, 08:22 PM

Pretty sure you need to run the bypass (like a BBC) because of the Vortec heads.

**Portland68** · 02-01-2020, 09:33 PM

I'm glad others brought up the bypass as I'm having a hard time finding a solution I like for my vortec. Edelbrock and others sell a coolant bypass that fits below the thermostat housing, but my concern is the line is 1/4 instead of 3/8 - what have others done for their vortec bypass?

02-01-2020, 10:04 PM

If I were to move the lower heater core hose to the intake (brass plug next to the thermostat housing) and run the top heater core hose to the water pump, that should do the same thing, right?? Would it do the same thing if I took the top heater core to the radiator? I would think that coolant would be bypassing under the thermostat at that point. Anyone have thoughts on this?

Daron65 · 02-02-2020, 11:00 AM

Quote:

Originally Posted by letsgofast

If I were to move the lower heater core hose to the intake (brass plug next to the thermostat housing) and run the top heater core hose to the water pump, that should do the same thing, right?? Would it do the same thing if I took the top heater core to the radiator? I would think that coolant would be bypassing under the thermostat at that point. Anyone have thoughts on this?

That is exactly how i run mine with my aftermarket heater. I have had NO problems. We have very similar engines.
You have a great looking build.

geezer#99 · 02-02-2020, 11:14 AM

Quote:

Originally Posted by letsgofast

If I were to move the lower heater core hose to the intake (brass plug next to the thermostat housing) and run the top heater core hose to the water pump, that should do the same thing, right?? Would it do the same thing if I took the top heater core to the radiator? I would think that coolant would be bypassing under the thermostat at that point. Anyone have thoughts on this?

Maybe, maybe not!
I dug this up for you.

https://www.flowkoolerwaterpumps.com...perature-spike

Time will tell.
If you get temp swings you might need a bypass.

garyd1961 · 02-12-2020, 11:00 PM

Quote:

Originally Posted by letsgofast

If I were to move the lower heater core hose to the intake (brass plug next to the thermostat housing) and run the top heater core hose to the water pump, that should do the same thing, right?? Would it do the same thing if I took the top heater core to the radiator? I would think that coolant would be bypassing under the thermostat at that point. Anyone have thoughts on this?

As.long as you don't have a cut off valve for the ac in the line this should be all you need.

02-02-2020, 01:08 AM

Quote:

Originally Posted by Portland68

I'm glad others brought up the bypass as I'm having a hard time finding a solution I like for my vortec. Edelbrock and others sell a coolant bypass that fits below the thermostat housing, but my concern is the line is 1/4 instead of 3/8 - what have others done for their vortec bypass?

Do you have a photo of your current setup?

01-24-2020, 11:29 PM	#1
letsgofast Guest Posts: n/a	Motor swap I’m going to post up the progress of the engine swap in my 72 C20. It might not be exciting but it will be cool to look back on. Started with a tired, stock 350. After getting it out, I sprayed the engine compartment with EZ OFF and power washed it. Attached Images Last edited by letsgofast; 01-26-2020 at 01:27 PM.

01-24-2020, 11:36 PM	#2
letsgofast Guest Posts: n/a	Re: Motor swap Hit it with Satin Rustoleum Attached Images Last edited by letsgofast; 01-25-2020 at 12:08 AM.

01-25-2020, 12:11 AM	#3
letsgofast Guest Posts: n/a	Re: Motor swap Newness Attached Images

01-25-2020, 12:16 AM	#4
letsgofast Guest Posts: n/a	Re: Motor swap Blueprint Engines 365/405 Attached Images

01-25-2020, 12:40 AM	#5
HeavyHauler Registered User Join Date: Nov 2011 Location: USA Posts: 401	Re: Motor swap That is going to look good! Did you get a good deal on the engine? Too bad they dont sell big blocks like that.

01-25-2020, 12:46 PM	#7
Ironangel Senior Member Join Date: Feb 2010 Location: Falls City, Nebraska "100 Miles From Nowhere" Posts: 2,219	Re: Motor swap Love those "Ochre" paint jobs! L-31 motor is a good choice, looks good! __________________ Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American"

01-25-2020, 01:30 PM	#8
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,281	Re: Motor swap Nice job on the prep work! That's the hardest part. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

01-25-2020, 05:18 PM	#10
ltdmstr Registered User Join Date: Jul 2016 Location: Deerfield IL Posts: 108	Re: Motor swap Holley 6210 spread bore is a great carb for those motors.

01-25-2020, 11:24 PM	#12
letsgofast Guest Posts: n/a	Re: Motor swap More progress today. I fixed a leak at the shifter shaft and changed the transmission filter today. I also installed a 2500 stall converter. Attached Images Last edited by letsgofast; 01-26-2020 at 01:33 AM.

01-26-2020, 02:56 AM	#13
External Registered User Join Date: Jun 2018 Location: Louisiana Posts: 185	Re: Motor swap Sub'd for the update on driving! __________________ '72 Chevy Custom Deluxe Highlander. Med Olive/White 350/200 ps,pb and Air Conditioning!

01-26-2020, 01:30 PM	#14
letsgofast Guest Posts: n/a	Re: Motor swap New trans cooler lines this morning and getting the motor out of the crate. Attached Images

01-26-2020, 01:36 PM	#15
Daron65 Registered User Join Date: Oct 2019 Location: Monaca, PA Western PA Posts: 93	Re: Motor swap I really enjoy this thread. Im excited about how it will drive. The blueprint 355 i put in my 71 is a great engine. Sounds great, and great fun to drive. Im sure you will be more than happy with it. __________________ 1971 Chevrolet C20, Blueprint 355. Holly Street Avenger 430HP. Turbo 350 1952 Chevrolet Deluxe. Stock. True survivor with 1 paint job 1953 Buick Special. GM 355. Just a good smooth engine.

02-01-2020, 07:06 PM	#16
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,712	Re: Motor swap Before you put coolant in it, your heater hose is on wrong. Supposed to be intake to bottom of heater core, top of core back to water pump or rad. Yours needs to go back to rad as you need that port on the water pump for the coolant bypass from the intake.

02-01-2020, 07:45 PM	#18
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,712	Re: Motor swap That would work.

02-01-2020, 08:22 PM	#19
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,979	Re: Motor swap Pretty sure you need to run the bypass (like a BBC) because of the Vortec heads. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ



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02-01-2020, 09:33 PM	#20
Portland68 Active Member Join Date: Apr 2017 Location: Portland, Oregon Posts: 186	Re: Motor swap I'm glad others brought up the bypass as I'm having a hard time finding a solution I like for my vortec. Edelbrock and others sell a coolant bypass that fits below the thermostat housing, but my concern is the line is 1/4 instead of 3/8 - what have others done for their vortec bypass?

02-01-2020, 10:04 PM	#21
letsgofast Guest Posts: n/a	Re: Motor swap If I were to move the lower heater core hose to the intake (brass plug next to the thermostat housing) and run the top heater core hose to the water pump, that should do the same thing, right?? Would it do the same thing if I took the top heater core to the radiator? I would think that coolant would be bypassing under the thermostat at that point. Anyone have thoughts on this?

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