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Chev V8 conversion set up question?

Discussion in '40- & 55-Series Tech' started by Gear, Apr 17, 2003.

  1. Gear

    Gear

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    I recently picked up a 68 FJ40 and with it came 2: 3-speed trans with vacuum transfer cases, a 4 speed newre TLC trans mated to the 4 speed t-case, I have a 350 and a TH350 available relatively cheap. My question is: Which set up is the best for a guy who wants to cruise the highway at 75 and still put-put around off-road. No crawling or anything serious off road. I'm sure I could find a sm420 or 465 easily. I have read that automatics are tougher to install. Which transfer case is more desirable to match up to a gm trans 3spd or 4spd? Which set up will be the cheapest and most reliable? I appreciate any opinions and help.
     
  2. megolfer

    megolfer

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    If you are going to be using it for a daily driver and running it on the highway a lot I would go with thw automatic.  If you do end up going automatic, there is an adaptor for sale on the sale section for a TH400 which is a stronger tranny than the th350.  I believe he wants around $300 for it and it has the cut drive shafts.  Its an AA adaptor so its a good quality.  You wont get a better deal. He is a super nice guy. Here is the link.

    http://www.ih8mud.com/cgi-bin/yabb/YaBB.pl?board=forsale;action=display;num=1049649827


    If you are going to go with a manual the sm420 is the cheapest and easiest way to go.  Its not the best tranny in traffic, and its old so it not a smooth shifter.  The sm465 is a newer granny 4speed and shifts a whole lot smoother.  It has syncros in all gears and in my opinion its a lot better tranny.  It does cost more money to install, but I think its worth it.  I am doing my conversion for around $500.  Just my 2 cents worth.

    I would go the auto if you are going to using it as a daily driver. If your not worried about getting low gears than this is the way to go. Also I would use the 3-speed case, it has lower gears and I think its easier to adapt. Not sure though.
     
  3. bsilva132

    bsilva132

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    If you want to go 75 down the freeway, do the auto or 465. The 420 is a good trany (I am putting one in my 40), but it isn't the smoothest shifting trany out there. As far as cheepest, the 350/420/3spd case would most likely be the cheapest as the 420 to 3spd adaptor is way cheaper than the ones for the auto and 465. I would suggest finding people who have this setup near you and drive their cruisers so you can compare yourself.
    -Brian
     
  4. sfrolich

    sfrolich

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    If you go manual, there is nothing better than a NV4500 5speed. The only case would be if you do extreme rock crawling.

    I regularly go down the highway at 80 mph at 2500 RPM in my 40.

    Scott
     
  5. megolfer

    megolfer

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    The only bad thing about the nv4500 is the price. You are looking at $800 or more for a good tranny then plus the adaptor, drivelines. By the time your done you will be close to $2000.
     
  6. PHAT MAX

    PHAT MAX

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    thanks for the plug! And that is 300 shipped anywhere. Hey your case is on the way!
     
  7. Gus

    Gus SILVER Star

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    I'd avoid the Th400 and the TH350, I've owned a cruiser with a TH400 and it was the biggest piece of s**t that I've ever had the displeasure to drive. With the auto my 40 couldn't even begin to crawl at all, it was, however, pretty fun in the sand. My family had a 3/4 ton Chevy work truck with a TH400 and it had to be replaced twice with in 115k, I've had bad luck with them. The SM465 would be pretty sweet with a 3speed t-case behind it, adapters for this swap are easy to come by. The stock cruiser 4 speed transmissions are pretty good for daily driving, maybe not as ideal for crawling and it's really easy to adapt a 3 speed t-case to one. I have to second sfrolich, the NV4500 5 speed is awsome, excellent on the highway and very strong. :G
     
  8. bodacious

    bodacious

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    hey if you want to go down the highway.. go with a 700r4 tranny it has a lower 1st gear and overdrive... and shifts nice and the price has come down.. get an 89 or later.. i have one in a 40 and my 45 pickup for years with no probs.. and it is the only way to go seeing that the 45 has been a daily driver for years.. i do know of an AA adapter for sale..dont know if its still around... dont go the 4 20 or 465 route... neither has an overdrive.. and both dont like going 75 unless your running 373's in your pumpkins..