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Discussion Starter #1
Hey Guys, Gave up on the engine swap in the DeVille. To many Headaches on that. So I going to see what the HT4100 can do. I thought I would start with a duel exhaust system. So I figure I might as well replace the manifold gaskets while I was at it, This is where it gets fun. I pull out the Haynes manual an it states I have to DROP the subframe to remove the rear manifold. This is a joke right? Had to be written by someone having a bad day? Anyone done this on a 85 Sedan DeVille (tranverse mounted engine) I sure would like to meet the idiot who laid out this set-up. It's one thing to mount a oil filter upside down on top of the engine, But drop the subframe to replace a gasket?? Good thing I love this car.
 

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You really SHOULD think about at least swappin to a 4.5 or 4.9, its really easy. Those 4.1's are crap, I blew 2 of em in about a year. There are NO performace parts for the 4.1, and not worth the money if you find any I don't know of. But it's just my 2cents.
D.
 

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Discussion Starter #3
Have you done one of these swaps? What would it take to get the 4.9 to work?I was told that the induction system would not work on my 85. I would love to dump the 4.1 and upgrade to something better.
 

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I heard a 4.9 will not work beucas eit is PFI, but a TBI 4.5 is almost a direct swap.... I would go for it besides far better engine, the performance goes liek this:

HT4100 4.5 4.9

hp: 125 180 200
tourqe: 200 255 275

plus the 4.5/4.9 are just better enignes, although the 4.5 is a bored out HT4100 and the 4.9 is a stroked 4.5, and they are pretty much the same, all the defects of the HT4100 were fixed in the 4.5.....
 

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Discussion Starter #5
Now that sounds more like it. That's a nice jump in power & tourqe for my little caddy. Going to have to look around for a 4.5. Thanks.
 

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You can use the intake and TBI setup from the 4.1 on the 4.9, just switch the blocks/heads. You'll need to re-use your TBI setup, intake and valve covers if I remember right. I did the same thing in my old 87 DeVille (R.I.P.)
D.
 

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Discussion Starter #7
Cool, This sounds better already. I can see the ricers in my rear view mirror already. Now to find the 4.9.
 

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NICE! You'll love it, the only thing that I didn't like was that I could tell it could run a lot better. Don't get me wrong, it's a deffinate improvement!!!!! I had mine running 14's, but that was with MUCHO! machine work. :bighead: If I remember right, the 4.3L truck throttle body spacers work w/the caddy TBI. Don't count on it thought, this was about 4 years ago. I've got a 4.9 that came stock now, finally. But, either way a bore out/redrill is cheap and did miricles on my old ride! Just a suggestion. ;)
Peace,
D.
 

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Discussion Starter #9
I also read that the 368 4-6-8 throttle body works. But he suggested that the intake should be ported to match. I spent years hot-rodding the small block chevy, But I love this little caddy. I'm going to go ahead with the duel exhaust system while I hunt down a 4.9. Also going to look into some ignition upgrades as well. It has the 'sport touring' suspension package, Not sure what that is exactly yet. Do want to make some spring/shock/swaybar mods on this little baby as well. I want to take it down to the silver state classic challange next fall to run the G.T. class, Not to mention show those little ricers what a caddy can do. Thanks for the help guys!! will be asking for more I'm sure.
 

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That portings a great idea, I had the stock TBI and intake worked out in my old deville, and it was great. The biggest problem is getting a chip for the mods, but it'll work without one (just not as well as it could). I'm working on a SB right now too, a 383 for my 86 monte carlo, but that's a summer-only car :).
Peace,
D.
 

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Discussion Starter #11
Earlier in this thread you ststed that you had mucho machine work done. If it's not to much to ask, could you explain what type of work you had done. And what worked best for you. Going to make a trip to my local 'auto recycling' place this week. Was thinking about getting a 4.9 there (Dirt Cheap) and having it re'built' so when I drop it in I know what I have. Has anyone ran N20 thru one of these??
 

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Deep Sleep said:
Earlier in this thread you ststed that you had mucho machine work done. If it's not to much to ask, could you explain what type of work you had done. And what worked best for you. Going to make a trip to my local 'auto recycling' place this week. Was thinking about getting a 4.9 there (Dirt Cheap) and having it re'built' so when I drop it in I know what I have. Has anyone ran N20 thru one of these??
It was about 5 years ago, but I'll try.... Intake ported & gasket matched, bored out to match the throttle body. Heads ported and gasket matched, 3 angle valve job (from an allante). Throttle body bored out, machined out throttle body spacer (about 2" thick if I remember right). Bored out .030 (gives you 5.0L BTW...). If there was more I can't remember right now (a bit drunk. LOL).
Hope this helps.
D.
 
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