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

justinburnett · 02-20-2011, 09:20 PM

Truck is a 1973 K20. Engine is from a 1987 Blazer (I think). Both 350, both carb'd, I don't know that the newer one really is a 1987 but it does have center bolt valve covers and a 1pc rear main. It doesn't seem to have any electronics though. What problems will I run into trying to put the blazer engine in my truck? I need this thing to be running in 13 days max. Thanks.

Toxic Redline · 02-20-2011, 09:36 PM

its the little stuff like wiring and vacuum/gas/emmisions lines that might hold you back, i think it should be pretty straight forward, i put a rebuild 70 350 in my 84 with no problem execpt me forgeting where wiring went. just a suggestion but label wires and take pictures during the tear down just to be on the safe side..

put the motor mounts off the 73 on the motor

justinburnett · 02-20-2011, 09:48 PM

I figured the mounts would be the same but it makes sense since I know the old ones fit. Thbanks, and my camera is standing by.
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bmchevy1979 · 02-20-2011, 10:39 PM

you need the correct flywheel/flexplate for the 1pc motor and as stated above keep good track of everything

justinburnett · 02-21-2011, 12:10 PM

came with a flexplate already attached. Going to change out the rear main though, since it'd be a shame to put it in and have it start blowing oil out the backside in 100 miles and have to pull it again.

MARKDTN · 02-21-2011, 01:48 PM

If you swap it complete with intake and flexplate you should not have any issues. Mounts are the same, exhaust is the same, accessory holes in the heads are the same. The main differences in these are the 1-pc rear seal that changes the flexplate and the center-bolt heads that changes the intake. The dipstick changing sides should no affect much.

justinburnett · 02-21-2011, 04:55 PM

Cool cool. Looking forward to it (except the weather). thought it was going to warm up but now they're calling for snow tomorrow-sunday

justinburnett · 02-22-2011, 01:55 AM

Does anyone know what bolts I need for the fuel pump? They seem to b e missing. Thanks.
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MARKDTN · 02-22-2011, 08:33 AM

Use off you old engine. If the '87 engine started life as a TBI engine it may not be drilled for a fuel pump rod. Thought you said both were carbed?

justinburnett · 02-22-2011, 05:40 PM

Yes both of them are carbed. The fuel pump looks the same but I wasn't sure if the newer one would be metric or not.
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02-20-2011, 09:20 PM	#1
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Engine swap Truck is a 1973 K20. Engine is from a 1987 Blazer (I think). Both 350, both carb'd, I don't know that the newer one really is a 1987 but it does have center bolt valve covers and a 1pc rear main. It doesn't seem to have any electronics though. What problems will I run into trying to put the blazer engine in my truck? I need this thing to be running in 13 days max. Thanks.

02-20-2011, 09:36 PM	#2
Toxic Redline Registered User Join Date: May 2010 Location: Ogden, Utah Posts: 219	Re: Engine swap its the little stuff like wiring and vacuum/gas/emmisions lines that might hold you back, i think it should be pretty straight forward, i put a rebuild 70 350 in my 84 with no problem execpt me forgeting where wiring went. just a suggestion but label wires and take pictures during the tear down just to be on the safe side.. put the motor mounts off the 73 on the motor __________________ 84 K20 Long Box W.I.P 78 Burb - parts now [Rolled] 68 c20 dump bed WHEN IN DOUBT--- FLOOR IT Last edited by Toxic Redline; 02-20-2011 at 09:37 PM. Reason: needed to

02-20-2011, 09:48 PM	#3
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: Engine swap I figured the mounts would be the same but it makes sense since I know the old ones fit. Thbanks, and my camera is standing by. Posted via Mobile Device

02-20-2011, 10:39 PM	#4
bmchevy1979 Registered User Join Date: Dec 2010 Location: Visalia, Ca Posts: 707	Re: Engine swap you need the correct flywheel/flexplate for the 1pc motor and as stated above keep good track of everything __________________ <Brandon> 1974 Chevrolet K5 Blazer 350sbc/SM465/NP205, dana44 front, corp 14bolt rear with 4.10s and a powertrax locker, custom rear bumper 400sbc in the works. 1981 GMC C1500 stepside 250i6, 3spd, 12bolt with 3.08s 2.5/4drop on 15x10 with 275/50r15 81 GMC C3500 cab-chassis dually with utility bed 350sbc, Sm465, 14bolt with 4.10s nv4500 getting ready to go in 1979 Chevrolet K5 R.I.P. http://67-72chevytrucks.com/vboard/s...d.php?t=434096 1976 Chevrolet C10 R.I.P. http://67-72chevytrucks.com/vboard/s...d.php?t=434195

02-21-2011, 12:10 PM	#5
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: Engine swap came with a flexplate already attached. Going to change out the rear main though, since it'd be a shame to put it in and have it start blowing oil out the backside in 100 miles and have to pull it again.

02-21-2011, 01:48 PM	#6
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,165	Re: Engine swap If you swap it complete with intake and flexplate you should not have any issues. Mounts are the same, exhaust is the same, accessory holes in the heads are the same. The main differences in these are the 1-pc rear seal that changes the flexplate and the center-bolt heads that changes the intake. The dipstick changing sides should no affect much. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

02-21-2011, 04:55 PM	#7
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: Engine swap Cool cool. Looking forward to it (except the weather). thought it was going to warm up but now they're calling for snow tomorrow-sunday

02-22-2011, 01:55 AM	#8
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: Engine swap Does anyone know what bolts I need for the fuel pump? They seem to b e missing. Thanks. Posted via Mobile Device

02-22-2011, 08:33 AM	#9
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,165	Re: Engine swap Use off you old engine. If the '87 engine started life as a TBI engine it may not be drilled for a fuel pump rod. Thought you said both were carbed? __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

02-22-2011, 05:40 PM	#10
justinburnett Registered User Join Date: Sep 2010 Location: The Dalles, OR Posts: 392	Re: Engine swap Yes both of them are carbed. The fuel pump looks the same but I wasn't sure if the newer one would be metric or not. Posted via Mobile Device



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