1979 K20 5.3 Swap

Discussion in 'Engine Swaps (Gas) LS, Vortec, LT1 , etc.' started by smurfasaur, Jan 27, 2018.

  1. rpcraft

    rpcraft Full Access Member

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    Well, in my case I could have done just the LS but I started doing that and realized I was cutting corners and doing things that would just cause me misery later, or worse yet be broke down on the road somewhere because of old trash the previous owner did that has nothing to do with the LS swap. I would rather take the time and do it right and have something that is dependable, reliable, and more importantly, not be having to trouble shoot every little issue that comes up, so I figure if I gotta redo the wiring harness, patch a couple of hole sin the floorboard, and then swap in a 14 bolt to withstand some occasional offroad abuse, it's just going to give me a more rewarding finished product. That being said Sunday I just uncurled a huge spaghetti monster from EZ-wiring and I'm trying to give myself the old pep talk that it is going to be fun, lol. It only took me about 2 hours to sort out the engine compartment and front blinker stuff. I also got all the wiring for the tail end of the truck sorted, now I just gottta climb under the dash and slay that beast. The only catch 22 about this harness is that it did not come with the bulkhead connector so I either need to pull my old one apart, clean it, de-pin it, and find some new pins for the new wiring, or close up the hole and use one of the more modern aftermarket bulkhead connectors.

    Not sure which direction I want to go, but I would rather avoid having to touch the old bulkhead connector with that nasty black gorilla snot they have on there.... If anyone knows of a source to get a new bulkhead connector I'd gladly take that advice!
     
  2. smurfasaur

    smurfasaur Full Access Member

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    I think the key is to do a TON of research, and get a engine/tranny with all accessories from a running rig. That’s been the biggest money suck for me is that I got a $500 engine/tranny which turned out to be worse than dog poo and both had to be rebuilt ($1800 tranny and $2000ish engine because the heads were junk), and then discovered along the way all the crap I needed instead of fully researching everything.

    Also I don’t advise buying a ton of parts right off the bat... Start your swap, then figure out what you need. I don’t think there’s a way around having to return things but it really sucks when you finally get to the fuel system and realize an in-tank pump would’ve been better but you’ve had the external pump too long so you can’t return it... Just for one example. Another is I bought two O2 sensors and then realized they were the wrong plug (had no idea there was different ones), but couldn’t return them either. $50 here and there is what kills the budget.

    The motor and trans is what for sure killed my budget. About $4k right there just in rebuilding those two. Get a good runner for $1k instead of a pile of crap for $500 and you’re $3500 ahead of me already.


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  3. rpcraft

    rpcraft Full Access Member

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    I emulate the sentiments. good reasaerch will help prevent spending money twice on some things and starting with a good known drivetrain unit will get you off to a good start.
     
  4. smurfasaur

    smurfasaur Full Access Member

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    Here’s a pic of the xmember. I actually think it’s a 2wd one that was modded to clear the front driveshaft
    [​IMG]
    [​IMG]


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  5. rpcraft

    rpcraft Full Access Member

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    Looks like the early model piece 4wd crossmember for use with a transfer case adapter with the long foot but it looks like someone further modified it for their own reasons with the flat cutout. Probably either trying to clearance for a dual exhaust or an issue with the front drive shaft rubbing. Hard to say. That is one of the 2 I currently have so it won't be needed. Thank you sir.
     
  6. HotRodPC

    HotRodPC Administrator Staff Member

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    That does appear to be the earlier 4x4 crossmember which uses the tall adapter. To the best of my knowledge there is only 3 different 4x4 crossmembers. There's that one used up until 83 or 84 that uses the tall adapter. Then there's the W crossmember that used the short adapter for 85 and 86, and then the wavy crossmember from 87 up with a big wider footprint than the W, and a notch for the exhaust to go under the crossmember on 1 side instead of over it. It also uses the short adapter. I have pics of all 3 if I can dig them up if you need them.
     
  7. rpcraft

    rpcraft Full Access Member

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    There is one that I have seen pictures of that used multiple pieces to support the side rail and if it wasn't for those pieces it would be kind of S shaped. General concensus is it may be a one ton or some heavy duty cross member but I think it may have been confused with a late 67 - 72 crossmember. Lemme see if I can find a picture here and now you got my wheels spinning again, lol.

    if it wasn't for that one though I'd say you got it on the nose, and the last one and the W one both run a short foot adapter (and more importantly at the same height). I'm not sure what forced the changed but that is the detail me and Scotty are trying to iron out, without shelling out a ton of money on cross members we won't have a use for afterwards, lol
     
  8. rpcraft

    rpcraft Full Access Member

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    Found it. Post #11 down the activity stream on this thread from earlier this year. My main goal is to just ensure that this cross member doesn't have to be factored in to the mix. I think it is essentially a more heavy duty version of the flat one like you and I have simply because it appears to use the same rubber bushings...

    http://www.gmsquarebody.com/threads/1-ton-crossmember.20980/
     
  9. smurfasaur

    smurfasaur Full Access Member

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    Interesting. Yep the cutout was to clear the driveshaft on the setup my truck came with (208/465). Even with the cutout there was only about 1/8” clearance for the front shaft


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  10. smurfasaur

    smurfasaur Full Access Member

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    Started fitting my JK fog lights. Definitely didn’t think cutting a 4” diameter hole in 1/2” plate would work that good. Bumper is definitely overkill and was definitely made in shop class or something but I like it. Makes for a damn good step to get into the engine bay

    [​IMG]


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  11. Crispy

    Crispy Full Access Member

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    Working on my swap now and was looking to run these headers. Do you have any pics of the header/exhaust modification that had to be done or can you explain what you did to make it work?
     
  12. smurfasaur

    smurfasaur Full Access Member

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    I can’t, because I actually haven’t done it yet. All I’m going to do is chop the ends off after the collector (about 8” or so of 2.5” pipe after the collector), weld in an O2 bung to the collector area, and then fab some 2.5” exhaust pipe the does a bit of an S shape (not really an S but it needs a good jog upwards in order to get to where it will pass the crossmember I also haven’t built yet).

    Probably doesn’t make much sense in words, but I attached a bad drawing of what I’m going to do. Not quite as dramatic as my drawing
    [​IMG]

    Also the actual header tubes hit the passenger side frame so I had to do about a 1” notch on the top and bottom frame rails. Not a ton but it’s more that I’d like

    All said and done, I would consider using the speed engineering headers with the Vband clamps mentioned earlier in this thread. IMO these long tubes have been more trouble than they’re worth (I think?).


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    Last edited: Mar 14, 2018
  13. Crispy

    Crispy Full Access Member

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    Thanks! I understood completely, but Photoshop skills helped haha. On the passenger side did all the primaries hit? I dont mind doing a little grinding like that. I've seen the mess created when guys run the truck manifolds and that was my original plan, not anymore! I've read the speed engineering headers dont fit 4wd applications, i've also read that they do fit 73-87's but not 62-72. With the lack of verification I found I think the price of the Camaro headers is worth the work you have to do if you dont want to run F body or TBSS manifolds, but you have more progress in than I do.

    Do you have your OEM crossmember on their now?
     
  14. smurfasaur

    smurfasaur Full Access Member

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    Arts and crafts was never my strong suit lol

    Not all the primaries on the passenger side hit, I want to say it was just the one closest to the cab but I can’t remember. I’ll snap a pic tonight. I hadn’t heard that about the speed engineering headers - that’s a bummer because they’re damn near the same price I paid for my eBay camaro headers

    I actually have the back end of the trans resting on a jack stand at the moment because the stock crossmember wasn’t even close to being useful - the goal is to get the crossmember fabbed up and the exhaust connected this weekend so I can start it without waking all of Washington lol. I’ll post pics of all the mods I have to do to the headers




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  15. Crispy

    Crispy Full Access Member

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    Thanks, I would appreciate the pics. No rush either.

    The price on the speed engineering headers is very fair imo, so much cheaper than other swap headers ive seen. Ill see if i can get some info on them and let you know what I find. I still havent bought mine but have read that the Camaro headers is where everyone is going nowadays for a more budget friendly swap.

    I see you have a 79 so your crossmember would definitely be useless. Im going from 700r4 to 4l60e so in theory everything should land right where it was.

    Keep up the good work, and try not to get too anxious, thats where mistakes happen and corners get cut. Im saying that as much for me as for you lol.
     

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