71 GMC engine swap-arino
 

Well guys this is going to probably be a lengthy thread but I'd rather start one and ask a bunch of different questions than 80 different threads. So here goes... :
I'm going to swap the motor out on my 71 GMC K2500 the engine that is currently in there has "issues" with cylinders 7 & 8. I pulled the valve covers and intake manifold. I have found bent push rods and stuck or bent valves also one broken exhaust valve spring (multiple pieces) I'm pretty sure I could probably get away with replacing heads, but I have an "L44" GM crate motor that I was looking to sell but didn't (I didn't think 1500 was too much for a crate motor, but apparently ppl in Phoenix do *shrugs*) this crate motor is a "1993 spec". GM part # 12681430 (discontinued/ superseded.) This engine was bought in 2017 and sat in it's crate in the plastic in a garage, until I got the truck in July. This crate motor has the spot for a mechanical fuel pump, but no hole to the cam and from what I've read probably doesn't have a pump lobe on the cam( but it is still a maybe).
Question 1) What fuel pump should I use as my truck doesn't have an EEC fuel tank and no way (that I'm aware of) for a "return line" from any pump? I was looking at the Carter #4594 or Facet solid state pump #40345 or #40109
2) Should I swap to a serpentine system or try and find new to me "correct" belt pullies?
3)What do I need to do to this engine before I swap it in ie check valvetrain lash, a marvel mystery oil "soak", etc.
4) Should I pull these rear oil galley plugs and "tap" them?
5) This doesn't appear to have the vertical center intake bolt holes, my Weiand Action Plus (8004) seems to sit flush. Fel-pro gasket #1205s-3 and send it?
For all of you guys that have done this before these may seem like silly questions but I've never swapped an engine before and most of the internet is such a pit of opinions built on lies and speculation that I'm more confused now than when I started.

Re: 71 GMC engine swap-arino
 

More pictures

Re: 71 GMC engine swap-arino
 

That is the later centerbolt heads so the center 2 intake holes are not at the same angle. You can "hog out" the holes in the intake and use wedge shims on those bolts or get a different intake.

Why can't you use the pulleys from your current engine? Serpentine is nice, but not necessary (and IMHO stay away from CS130 alternators).

Without taking it apart you will have to use an electric fuel pump.

I don't think I would do anything special other than prime well with a drill and rotate the crank a couple times while doing it. It looks pretty clean to me.

I would not do anything with plugs?

Also, this is not a roller cam engine. Be sure to use a high zinc oil and follow the break in process to the letter.

Re: 71 GMC engine swap-arino
 

Staying away from the CS series alternators, gonna try and stick with the 12si I(94 amp) just got.
Now that you mention it I see that those center holes threads are at a different angle... Any idea where to get those shims/washers? I'd rather not hog out the holes in the intake if I don't have to.
I'm going eventually add A/C so I was trying to plan ahead and get a long nose water pump which means my current pullies will be un-usable.
I was also planning on using the Amsoil "break-in" high zinc oil, How do I prime it with a drill? Again newbie here. Thank you for the reply and help.

Re: 71 GMC engine swap-arino
 

Priming tool

https://www.amazon.com/Htostar-Racin...35b9659f0fc071

Re: 71 GMC engine swap-arino
 

You rock I didn't know that even existed. 👍

Re: 71 GMC engine swap-arino
 

Intake bolt wedges
https://www.holley.com/products/disc...ct/parts/90748
These are discontinued but you can make something similar. I think you will have to at least enlarge the holes in the intake to make them work.

You can get A/C on a 67-72 so no need to go long pump for that. I would not use an A6 compressor, but there are kits to put a Sanden on which will have the brackets you need anyway. And if you do go serpentine, get one without an R4 compressor like a Corvette with Nippendenso or the later 4.3 or 5.7 with the silver compressor and then get a Nippendenso to replace it (not an offshore). With any of these you will need a different alternator and I would want a CS144 not a CS130.
https://www.classicindustries.com/pr...Gmph3crLtlBrGx


To prime the engine you need a priming tool or an old cut off distributor. It's possible to just use a screwdriver with no handle, but I would want the whole thing so it will oil the top end since this engine has been sitting and with all the problems with breaking in flat tappet cams. Some are just shafts that don't close a gap to oil the top end.
https://www.summitracing.com/parts/p...gaAgQnEALw_wcB

Re: 71 GMC engine swap-arino
 

You can "rent" one of those priming tools from Oriellys or Autozone. You buy it, use it and return it for the money. I bought one and kept it, since I used to use one quite a bit.

Re: 71 GMC engine swap-arino
 

If the heads are cast 14102191/14102193 or 14101081/14101083 you will need the correct manifold. Edelbrock 2104 is made for those heads with the 4 inner mounting bolts at the correct angle.

Mine had a Professional Products manifold with the wedges, it is a dual set-up for 1955-95 heads.

Re: 71 GMC engine swap-arino
 

More pics of the wedges and how the inner 4 mounting holes are oblong to fit both styles of heads

Re: 71 GMC engine swap-arino
 

10159550/10159552 are also 1987-95 heads that have the offset inner mounting holes too, pull a valve cover off to see what heads are installed.

Re: 71 GMC engine swap-arino
 

The engine is cast as a 10243880 so it should be a roller cam but yours looks like its missing the lifter retainer and has flat tappet lifters.

https://www.hotrod.com/how-to/ccrp-0...y-small-block/

Re: 71 GMC engine swap-arino
 

That is great information and an informative article. Thank you.

Re: 71 GMC engine swap-arino
 

[/QUOTE]

You can get A/C on a 67-72 so no need to go long pump for that. I would not use an A6 compressor, but there are kits to put a Sanden on which will have the brackets you need anyway. And if you do go serpentine, get one without an R4 compressor like a Corvette with Nippendenso or the later 4.3 or 5.7 with the silver compressor and then get a Nippendenso to replace it (not an offshore). With any of these you will need a different alternator and I would want a CS144 not a CS130.
https://www.classicindustries.com/pr...Gmph3crLtlBrGx[/QUOTE]

This is the set up I found yesterday that I was thinking about going to/using.

Re: 71 GMC engine swap-arino
 

Thank you again to everyone who has contributed, this is really helpful to me and I appreciate it. 👍

Re: 71 GMC engine swap-arino
 

I made one out of an old distributor about 45 years ago with a hacksaw.

Re: 71 GMC engine swap-arino
 

Suggestions for a good "break-in" oil? I'm going to do the GM procedure which says 10w30 but most people I have talked to say 20w50 and a high zinc oil and/or additive. Opinions welcome.

Re: 71 GMC engine swap-arino
 

I saw that method too, I've got a neighbour that has the fancy tool he is going to let me borrow... I do think it is hilarious that when ppl find out your are swapping an engine they ALL come out of the wood work. At least in my circle of friends and family... All want to watch, no one wants to be "hands on"... *laughs*

Re: 71 GMC engine swap-arino
 

Should I put assembly lube down the push rod guides? What about on the rockers?

Re: 71 GMC engine swap-arino
 

You can get A/C on a 67-72 so no need to go long pump for that. I would not use an A6 compressor, but there are kits to put a Sanden on which will have the brackets you need anyway. And if you do go serpentine, get one without an R4 compressor like a Corvette with Nippendenso or the later 4.3 or 5.7 with the silver compressor and then get a Nippendenso to replace it (not an offshore). With any of these you will need a different alternator and I would want a CS144 not a CS130.
https://www.classicindustries.com/pr...Gmph3crLtlBrGx[/QUOTE]

This is the set up I found yesterday that I was thinking about going to/using.[/QUOTE]

That is an R4 compressor. In my experience they do not like to sit. If you use it very regularly and defrost in winter it will be OK. If you park it in Winter and never use defrost and it sits for months, you may have seal issues.

Early C4 Corvettes use a similar setup with R4. Later C4 (Tuned Port, not LT1) use a Nippendenso compressor.

If you must have serpentine, I would look on late 4.3 S10 Blazers. They have the silver compressor. The offshore new ones are junk but the real Nippendenso ones hold up pretty well. Whatever you do you will need new hoses. I put a Corvette R4 setup on a '72 for a guy once and made the factory hose work but it was really too tight since the R4 is shorter than an A6.

Also, lots of late blocks have roller cam provisions. Yours has provisions but has a flat tappet camshaft. I would not tear down a new crate to change the cam but that's me. The flat cam will be fine if broken in right IMHO.

Re: 71 GMC engine swap-arino
 

When you run the oil pump with the drill and adapter you will get oil to the pushrods. I would not add anything else. Just rotate the engine a few times while priming and I think you will be fine.

Re: 71 GMC engine swap-arino
 

I love this thread! I'll be watching, and NOT helping either!:lol:

Re: 71 GMC engine swap-arino
 

This is the set up I found yesterday that I was thinking about going to/using.[/QUOTE]

That is an R4 compressor. In my experience they do not like to sit. If you use it very regularly and defrost in winter it will be OK. If you park it in Winter and never use defrost and it sits for months, you may have seal issues.

Early C4 Corvettes use a similar setup with R4. Later C4 (Tuned Port, not LT1) use a Nippendenso compressor.

If you must have serpentine, I would look on late 4.3 S10 Blazers. They have the silver compressor. The offshore new ones are junk but the real Nippendenso ones hold up pretty well. Whatever you do you will need new hoses. I put a Corvette R4 setup on a '72 for a guy once and made the factory hose work but it was really too tight since the R4 is shorter than an A6.

Also, lots of late blocks have roller cam provisions. Yours has provisions but has a flat tappet camshaft. I would not tear down a new crate to change the cam but that's me. The flat cam will be fine if broken in right IMHO.[/QUOTE]

Right on, good advise. 👍 I honestly don't want to tear into the engine in any way, I was just going to swap valve covers (L to R and vice versa) and while they were off, put a little assembly lube on the contact points. Also I was going to put some assembly lube on the push rod guides where you see them in the "valley" of the block between the heads.
Thank you again for the continued help. I feel like I'm learning alot.

Re: 71 GMC engine swap-arino
 

Ah, ok sounds good... Any suggestions on oil/zinc addatives?

Re: 71 GMC engine swap-arino
 

I've already started to set up a lawn chair gallery... You are welcome to join... Popcorn is tree-fidy... *laughs*