Another A/C for SBC Swap thread

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Jul 20, 2006
Ok this thread is mainly to show the hose block I have and to note the issues. Engine is a 5.7 SBC Vortec from a 1999 GMC Yukon, Truck is 1986 FJ60. I'm posting 3 pics at a time so it will be a few posts initially to show my issue. I ecplain a little bit more down in the thread but the issue is that the A/C adapter block I have that mates the hoses to the a/c compress does nto fit the compressor properly because the block is flat on the bottom while the mating surface of the compressor has different depth between the two holes. I've got to round up my factory a/c hose that came with teh 5.7 to look at the factory GM block...

So the issue right now for me is getting the plubming done.... Either I find the right adatper block to use or I get a GM OEM compresor hose and I modifty it to work using its OEM block.
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more pics

more related pictures. first picture shows the a/c hose block with the hoses disconnected. Notice the 2nd and 3rd picture...the ports or holes in the A/C compressor have different depth, thus the flat bottom of the A/C hose block does not seal down on teh compressor properly. Its a little hard to see but notice the tip of my knife. FYI the compressor is the old one we are just just using to mock things up and so I knowi ts nasty and dirty and all fo that...I have a brand new compressor ready to go on once the a/c block business is solved.
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more related A/C pics

some additional pictures. Ok see the A/C hose first pic its shwon upside down...with the seals. Notice in 3rd picture that the bottom of hte block is flat.
more additional pictures

last of the set.
ok these last series of pictures show the old A/C hose that came with my engine...after examination there is a clear difference in the depth of the two ports that mate with the top of the compressor on this OEM GM hose assembly vs. the adatper block from "doc's blocks"... so clearly at present time I have an adapter that will not seal or work propertly.
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last two pics...once again notice the knife blade and the depth of the blocks ports where it mates with the compressor. So I'm going to see if I can get the "hose guy" to make hoses using part of the GM hose assembly or if I have to...just the compressor block portion. Wish I had paid attention to these details previously, but that did not happen and so I'm dead into A/C season with half the stuff I need. I posted all these pictures up so it may help someone else and they don't have to repeat the same mistake.
Hey Elbert,
Now that I see your pic's I understand the problem. I think the solution is Doc's #AA1288 which shows the differing heights of the block. I'm posting their drawing of said item. On this one, both pilots are the same size.
Hope this helps,

I'll look on their site again.....I'm leaning towards getting a GM OEM hose hacked up but I think I will go on and order the block from them (doc's blocks)... on the odd chance it may work, hard to beat the quality of the GM OEM stuff though, on A/C my view.

Thanks...for the input.


Is that part number good? I don't see it listed on their web site but not sure how much of their product line is actually on the web. I'll try to call them tomorrow if work is not in total meltdown...(we are moving @ work) what fun :(

Never mind on the question...

Looks like I need either the AA0443 or the AA1288, from the catalog (09 version) I had to dowload it shows that the two blocks are the same except the fittings are reversed. At approx $20.00 I'll order one of each if they still make them. I noticed in the catalog that is says "tall step" the pic, maybe that's a reference to the differences I've noted above. Maybe I'm crazy but it would be good to list these items by the make and model vehicle and engine size...but that might be logical.
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I went ahead and ordered teh 1288 block in case I ever need to resort to AN style hoses.... but for right now I took the GM hose and had a local guy cut off the ends and mate the toyota fitting that connects to the condensor on one end plus some hose and then a 90 degree fitting that will mate to the evap core fitting at the firewall plus some hose. To allow the crazy large totyota fitting to go back through the radiator core I had to enlarge the hole along the side of the radiator at the core support by some 1.5 inches or so (no other way to get that fitting through the radiator support otherwise.) this one be one advanage of running the adapter block from docs block. in that you are dealing wiith two hoses and an adapter block. WIth the gm hybrid hose setup you are dealing with one large hose assembly (similar to what GM vehicles run).
Got the hybrid hose installed and everything looks good

Next step is to get truck back over to friends hose so he can swap over new compressor and dryer then pull a long vaccum and then charge with freon once system integrity is known. Hopefully the trick with the neg side of the coil wire will allow the toyota ac amp to control the cycling of the compressor.

I was going to see about installing the pusher fan too, but ran out of time. Not sure my 12 inch pusher fan will work, I may have to go to a 10inch fan. RIght now I want to get a/c goign and well then see how the air flow is and how hot it runs once we get "cold air"...
A/C adapter block

Trying to some kind of security token error. I'll add text later if this works.

Block below is the AA1288 and looks to work with the compressor
I have that mates with the 5.7 Vortec. Other adatper block pictured above will not work. The AA1288 is not shown on doc's blocks web site, you have
to download the old catelog and hunt through the fittings.

Anway...trying to get up with my friend to charge the ac and see what we can do about getting it to work.

Just a question for those who have A/C running in their V-8 swap FJ60... What kind of temps are you seeing? My assumption is something 5 to 10F above your normal OP temp?

Between offroad trips and taking two steps back for every step forward I still don't have a/c yet but as of latest meeting of the minds we should be close by end of next week.

Anyway post up if you have some good numbers...I was hoping to have a/c by last weekend as it was really hot on our weekend at the "cove" near Tracy City, TN.
Well it looks like I'm my most favorite poster...oh well I guess I'll keep the current trend. Finally was able to get my friend to assist with A/C setup. See some background above. Took the LC over to his house yesterday...he swapped over new compressor, we previously had connected the tach signal wire from my PCM to the negative side of the coil. Then the plan was to use the toyota a/c compressor trigger wire to trigger a relay that in turn would energize the clutch on the compressor. So...I don't have the truck back but friend called me this morning to say I have cold a/c now :) he swapped compressors as noted, he pulled a vaccum on the system (initally had small leak on fitting at a/c hose, which another friend had told me aobut so I had new fitting) installed new fitting, pulled vaccum for about an hour...system held vaccum, he then charged with R-12 freon.

I hope I'm not bragging too soon but unless the system leaks down for some crazy reason I should be good. I'll post up some pictures by this weeked if all turns out. It will be a great day to have nice cold A/C , since the engine swap I never seemed to get around to fixing this...well the meltdown about a month ago at the COVE got me real motivated to get this fixed.

Next related project will be to install an electirc pusher fan on the D/S of the radiator to assist in air flow across the condensor when required....I'm hoping for "ice cubes" out the vents :)
Good to hear yah got the AC going...!!!
Does your ECU have fan control? Some do and in my case it had both 'A' and 'B' fan control. If I recall correctly from my qwik look at the donor's FSM the 'B' fan comes on with the compressor clutch. FFT with regards to your pusher idea? I'm thinking that I'll be putting a pusher on for when the A/C is on, but airflow thru the condensor isn't great. Like stuck in traffic or the :princess: co-pilot decides that she needs it in the middle of a slow trail.
I don't think my ECU has fan controls...I have a spal fan and also a spal fan relay + harness. I think I'm going to setup the fan where it comes on auto with the A/c and then in the cab I'm thinking about a toggle that will have manual off and manual on...


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I'm not sure with the vortec but with mine I wired the idle up wire from the ecm into the fan control as well so flipping the a/c on with the Toyota switch tells the ecm the a/c is on and to idle up. The couple hundred rpms really smooth it out with the a/c on.
If I can get the idle up function to work without too much pain I'll do it. Not sure my harness has a breakout for a/c on or idle up function. I know its part of the ECM but not sure its part of my wiring harness. I'll look into that, or may have to figure out which area to tap into on the ECM.
The pusher fan I did on mine really did make a big difference.

My engine temps are no different with the AC running than with it off.

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