Which engine for rebuild ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TexasC10 · 09-08-2013, 03:32 AM

My 70 truck had a year 68 inline 6 mounted that started smoking really bad 2 months ago and lifters knocking like crazy.
So pulled it out and installed a used (low-mileage but have my doubts)
250 engine from a 1978 Nova.
Was told it only had 80.000 miles but not sure....
Anyway the "newer" engine has integrated intake & exhaust manifold and now
it leaks anti-freeze around the rear section when I turn the truck off.
A small stream can be seen on the left side of the engine block...so
I guess it's time for a decision what to do next.
My question is, which engine would be best for a complete rebuild,
the 250 engine from 1968 with seperate manifold and intake or the "newer" 1968 250 engine ?
I called around to a couple of different machine-shops and was told the integrated engine usually has cracked heads and not worthy trowing money at.
So asking you guys for advice or comments what to do ?

TexasC10 · 09-08-2013, 03:37 AM

Forgot to mention the "newer engine" has a couple of lifter noise, but no smoke and no water in the oil, runs strong but leaking from the rear head section...

SCHRUMGMC · 09-08-2013, 03:59 AM

How much is a rebuild ?

TexasC10 · 09-08-2013, 04:02 AM

$ 1000 total

SCHRUMGMC · 09-08-2013, 04:14 AM

Dang, I'm sure I could probably find it cheaper than that

TexasC10 · 09-08-2013, 04:23 AM

Well, I called around Houston, they wanted between $1000 and $1.300 + tax for a complete rebuild with new pistons, bearings, lifters and all.

**Palf70Step** · 09-08-2013, 08:14 AM

Use the separate head. You can use either block, but the integrated heads tend to crack and don't give you much for performance/improvement options. And as you are seeing, builidng a straight 6 isn't very cheap. That is why many folks go to the V8 as it turns out to be cheaper. I love the straight 6's though. Wish I had never gotten rid of the one in my 70.

19673ontree · 09-08-2013, 08:34 AM

Id rebuild the 68 250 one of these days im gonna rebuild a 250 for my 67 those engines are wonderfull when in good condition ,
Posted via Mobile Device

cdowns · 09-08-2013, 08:39 AM

i am a huge fan of the crate engine programs

rebuild writeups like this have been frequent over the years
http://67-72chevytrucks.com/vboard/s...d.php?t=594903

In The Ten Ring · 09-08-2013, 11:24 AM

From what I have read on here, crate engines are the cheaper way to go unless one can do the work themselves. I have no experience in the area.

**WIDESIDE72** · 09-08-2013, 01:50 PM

I believe the blocks are the same, heads will swap. If so, do a compression and leak down test on he interfarted head engine. If it is good other than the leak pull the no int head off the 68 motor, get it rebuklt and install on the int head motor.
Posted via Mobile Device

09-08-2013, 03:32 AM	#1
TexasC10 Registered User Join Date: Aug 2012 Location: Houston,Texas Posts: 30	Which engine for rebuild ? My 70 truck had a year 68 inline 6 mounted that started smoking really bad 2 months ago and lifters knocking like crazy. So pulled it out and installed a used (low-mileage but have my doubts) 250 engine from a 1978 Nova. Was told it only had 80.000 miles but not sure.... Anyway the "newer" engine has integrated intake & exhaust manifold and now it leaks anti-freeze around the rear section when I turn the truck off. A small stream can be seen on the left side of the engine block...so I guess it's time for a decision what to do next. My question is, which engine would be best for a complete rebuild, the 250 engine from 1968 with seperate manifold and intake or the "newer" 1968 250 engine ? I called around to a couple of different machine-shops and was told the integrated engine usually has cracked heads and not worthy trowing money at. So asking you guys for advice or comments what to do ?

09-08-2013, 03:37 AM	#2
TexasC10 Registered User Join Date: Aug 2012 Location: Houston,Texas Posts: 30	Re: Which engine for rebuild ? Forgot to mention the "newer engine" has a couple of lifter noise, but no smoke and no water in the oil, runs strong but leaking from the rear head section...

09-08-2013, 03:59 AM	#3
SCHRUMGMC Registered User Join Date: Dec 2012 Location: North Carolina Posts: 4,989	Re: Which engine for rebuild ? How much is a rebuild ? __________________ 1971 GMC Sierra 1959 GMC 100

09-08-2013, 04:02 AM	#4
TexasC10 Registered User Join Date: Aug 2012 Location: Houston,Texas Posts: 30	Re: Which engine for rebuild ? $ 1000 total

09-08-2013, 04:14 AM	#5
SCHRUMGMC Registered User Join Date: Dec 2012 Location: North Carolina Posts: 4,989	Re: Which engine for rebuild ? Dang, I'm sure I could probably find it cheaper than that __________________ 1971 GMC Sierra 1959 GMC 100

09-08-2013, 04:23 AM	#6
TexasC10 Registered User Join Date: Aug 2012 Location: Houston,Texas Posts: 30	Re: Which engine for rebuild ? Well, I called around Houston, they wanted between $1000 and $1.300 + tax for a complete rebuild with new pistons, bearings, lifters and all.

09-08-2013, 08:14 AM	#7
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,268	Re: Which engine for rebuild ? Use the separate head. You can use either block, but the integrated heads tend to crack and don't give you much for performance/improvement options. And as you are seeing, builidng a straight 6 isn't very cheap. That is why many folks go to the V8 as it turns out to be cheaper. I love the straight 6's though. Wish I had never gotten rid of the one in my 70. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

09-08-2013, 08:34 AM	#8
19673ontree CAN'T FIX NOTHIN Join Date: Sep 2006 Location: SOUTHRUST VIRGINIA !!! Posts: 2,112	Re: Which engine for rebuild ? Id rebuild the 68 250 one of these days im gonna rebuild a 250 for my 67 those engines are wonderfull when in good condition , Posted via Mobile Device __________________ 1967 C10 Shortbed Fleetside Small back glass 6 cyl 3spd on the tree 3.08 gears underdash AC

09-08-2013, 08:39 AM	#9
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Which engine for rebuild ? i am a huge fan of the crate engine programs rebuild writeups like this have been frequent over the years http://67-72chevytrucks.com/vboard/s...d.php?t=594903 __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

09-08-2013, 11:24 AM	#10
In The Ten Ring Registered User Join Date: Jun 2013 Location: West Virginia Posts: 6,427	Re: Which engine for rebuild ? From what I have read on here, crate engines are the cheaper way to go unless one can do the work themselves. I have no experience in the area.

09-08-2013, 01:50 PM	#11
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,500	Re: Which engine for rebuild ? I believe the blocks are the same, heads will swap. If so, do a compression and leak down test on he interfarted head engine. If it is good other than the leak pull the no int head off the 68 motor, get it rebuklt and install on the int head motor. Posted via Mobile Device



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