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998 build research

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Thikstik View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thikstik Quote  Post ReplyReply Direct Link To This Post Posted: Apr/25/2018 at 2:17am
That said, these trans are OLD. So there's not many guys left that know them.  As rudimentary as they are,  a young builder that may have never even touched a 904/727 will cost you. Ironic.   
75 gremlin x, jeep 4.0 headed 258,
264H Cliff cam, intake,header. 390 holley. I want a 282 VAM motor!

AC/PS/PDB.

72 AMX , 304 2bbl, 3speed, now disks...probably will sell, want an automatic /AC.

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Ken_Parkman View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken_Parkman Quote  Post ReplyReply Direct Link To This Post Posted: Apr/25/2018 at 11:08am
998 has 4 disc clutch and 999 has 5 disc clutch, direct bolt in. Factory upgrade parts are easy and cheap. I generally do not like the wide ratio gear sets. The 'flats' style pump drive seems a better idea as some have seen converter neck failures.

I have had poor durability with 727 in race use and always recommend an upgrade to the 999. The drum in the 727 is so heavy that when you pull second the band has to stop all that weight instantly. Then pull 3rd and the high/reverse clutch has to instantly bring all that weigh to input shaft speed, which should be your converter stall rpm.

I have personally watched 2 (two) 727's explode the drum, rip the floor out of the car, and spray tranny oil on the inside of the windshield. I would never use one in a race application without a billet drum.

That's why the smaller 904/998/999 is so much a better tranny. There is a point where the smaller gearset is not strong enough, but as long as the tranny is put together right it seems a 401 is no issue. As well the 904 already has the bolt in sprag.

Street use, HD, towing etc that slug 727 is OK.

The mopar tranny's are incredibly easy to build. It's good to have a guy with race mopar experience to know all the mix and match components as there are a lot of options. Someone like Pat at SMR has piles of stuff and knows the interchange. He was a big help building the AMC A500 OD.

Edited by Ken_Parkman - Apr/25/2018 at 11:16am
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Thikstik View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Thikstik Quote  Post ReplyReply Direct Link To This Post Posted: Apr/25/2018 at 11:50am
Interesting info...i didnt know the 727 wasnt John Freakin Wayne like GM's 400. The old 3 speed trannys we all remember were all the same regarding the drum having to halt.  It is the Simpson gear stackup.  I do have the old article on how good the 904 could be.  IIRC, it is called "The Baby 727"?  It spoke of being less parasitic and how strong it can be.  
Pat at SMR is great.  Can you say if Mopar has a newer synthetic fluid like GM now uses? i wonder if we could use it which would be mixing it to some degree.

75 gremlin x, jeep 4.0 headed 258,
264H Cliff cam, intake,header. 390 holley. I want a 282 VAM motor!

AC/PS/PDB.

72 AMX , 304 2bbl, 3speed, now disks...probably will sell, want an automatic /AC.

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gremlinsteve View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: May/01/2018 at 2:25pm
Thanks

I've reached out to smr. Awaiting there response

I would love to have the fourth gear. But how much work is it to install into a gremlin
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SC397 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SC397 Quote  Post ReplyReply Direct Link To This Post Posted: May/01/2018 at 3:06pm
Originally posted by gremlinsteve gremlinsteve wrote:

I'm trying to determine who builds a good 998 amc
I am going to maintain the trans that came in my gremlin
And it's soon to have a 500-520 hp 401 in it

So I am obviously interested in getting this transmission built to handle
And give me good performance

Any particular kits or parts I should be after?   No racing
Or burnouts.   It's a column shift car so no reverse manual v bodies


A few of us locals use the 999/904 for drag racing. My Buddy Brad currently runs one behind his 650 HP 427AMC. We have a local guy in Michigan who builds our 727's and 904's for us including Brad's and does a great job. As reasonable as he is it would probably be worth the effort to ship it to him to rebuild.
Torqueflites By Randy!! Also Ring & Pinions..
Randys Martin # 734-718-6831
Marrtin & Son Auto Repair
734 697 7765
401 Sumpter Rd.
Belleville, MI 48111



Edited by SC397 - May/01/2018 at 9:14pm
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