304 flexplate not mating to 727 torq. converter

[monstermike]

Hey guy's

I need some help with this one please! I am trying to drop a 304 into a 1984 j-10 that used to have a 360. ( I know it sounds like a wimp out on displacement but $$$ was a big factor in this one, and I got a reman 304 for a killer price).

I did get a 304 flex plate and h/balancer and tried to drop the engine in but the flex plate does not have holes that line up with the torq. converter bolt holes?

I thought I was in good getting a 304 flex plate out of a 1975 cj5 but I am now stumped!
The tranny is a 727 and it's in great shape.

Thanks for any help!!

Mike

[BJ's Off-Road]

A 1975 CJ would have a TH400 for a transmission so the flexplate won't bolt up to the 727.

You need to get a new flexplate. Try a 1977ish AMC Hornet with a 304. The AMC cars in the 70's used the 727 transmissions so this should work out for you.

[monstermike]

Thank you for your help!

I will go on a search for that flex plate asap, and I will remember BJ's off road !

Thanks again!!

[PavementPounder]

Originally Posted by BJ's Off-Road

A 1975 CJ would have a TH400 for a transmission so the flexplate won't bolt up to the 727.

No, it wouldn't. The TH400 was not used until the CJ-7 came out in 1976. CJ-5's never had automatics.

Originally Posted by BJ's Off-Road

You need to get a new flexplate. Try a 1977ish AMC Hornet with a 304. The AMC cars in the 70's used the 727 transmissions so this should work out for you.

I agree on the potential source for the solution being an AMC car application, but not that particular model. Look up 304 Madators from 72-up with the heavy-duty trans option, which would be a 727. Otherwise, the 304 most commonly got the TF-998.

http://www.matadorcoupe.com/trannyspecs.htm

Originally Posted by Matadorcoupe.com

TF-904/998/727 is a Chrysler tranny that was used for many years in all Chrysler products. The internals exchange easily, but the exterior is AMC only. TF-904 is light duty and was originally used with Chrysler 4 and 6 cyl engines starting 1960, some early 273 V8s also got this tranny. Also some mid-size Chryslers with 318 got this tranny. TF-904 has 3 pinion planetaries and a single wrap rear band. TF-904 was available with in 2 ratios, a wide ratio with four cylinder engines, a standard ratio 904 with sixes. TF-904 uses the same output shaft and seal as the T-4 and T-5. TF-909 used in Jeeps, is a 904 with a lock-up torque converter. TF-998 was only used behind the 258 only in the Eagle. All other 258s in cars got the TF-904 TF-998 was used in all 304s in cars starting from '72 except some HD applications which got the TF-727. TF-998 originally used with Chrysler small V8s (318). TF-998 has a larger front servo, 4 pinion planetaries and a double warp rear band. This was the original lock up converter tranny. TF-999 originally used with 360 Chryslers, possibly also in later FSJs. TF-999 is same as 998 except for 5 plate front clutch, wider front band. TF-998/9 can be indentified from the 904 by the two external ribs on the case above the rear servo. TF-727 is a very heavy duty transmission, can hold almost anything, but on the downside is very heavy, and in this way considered inappropriate by some for drag racing use. TF-727 was also available as a heavy duty option in big cars with a 6 cyl. and Wagoneers with 6 cyl '80-'83 and Grand Wagoneers from '84-'87. TF-727 was used in Jeeps from '80 - '92. TF-727 case is 16" long and 14 bolts hold in the pan. Gear Ratios 2.45(1st) 1.45(2nd)) 1.00(third).

[BJ's Off-Road]

Originally Posted by PavementPounder

No, it wouldn't. The TH400 was not used until the CJ-7 came out in 1976. CJ-5's never had automatics.

He must have the year wrong. Any CJ that had an automatic in that ERA was a TH400. Used to have a CJ, don't anymore, glad I don't.

Originally Posted by PavementPounder

I agree on the potential source for the solution being an AMC car application, but not that particular model. Look up 304 Madators from 72-up with the heavy-duty trans option, which would be a 727. Otherwise, the 304 most commonly got the TF-998.

I show a 72 Matador and a 77 Hornet use the same flexplate on a 304.

[PavementPounder]

Originally Posted by BJ's Off-Road

I show a 72 Matador and a 77 Hornet use the same flexplate on a 304.

Okay, what's your source so we can be on the same page.

This is exactly why I pasted in that data from Matadorcoupe.com, which is found on almost all the other AMC car sites (such as AMC Hornet.com). It says the 998 was used behind the 304, except for in HD applications.

Using Rock Auto as a reference, the same part # is listed for the flexplate in the 74+ Hornets and Madators (Dorman part # 04302) and it actually says "TF-727", which conflicts with the 998 information. The second issue is that the same flexplate part number (04302) is also listed for the 360.

Tooth count, OD, and pitch are the same, but the 304 and 360 should have different balance, correct?

[carnuck]

304/360 are close in balance. 401 is hugely different and 6 cyl is zero balanced. The 727 and 999 use the same pattern on the flexplate. 904/998 is smaller.

[PlazJ]

Hey guys, just scanning the net for info, ran accross your discussion and wanted to add a bit of info.

They're rarer, but there were serveral models of AMC in the 70's that came with the HD option of a 304 and a 727 transmission. I personally have the flexplate and 727 that I pulled from a 304 1974 Hornet with the HD option. If you're scouting salvage yards probably the quickest way to know what your looking at is to check the transmission pan shape (if the tranny's still in). If the tranny's out then it's going to be tough. All the Chryslers look similar at a quick glance but the pan on the 727 is different from the others.



The top picture is what a 727 looks like so you'll know it got the right flex plate. The bottom picture is the shape for the 904, 998 and 999. Good luck with your rebuild.

[PlazJ]

BTW, the 304 and 360 are close but not balanced the same. Don't mix the flex plates.

[iagmc]

cjs in the pre 76 all had manuals? am I wrong? When I looked at puting the t400 in mine it was a tad to short, like i would have to run a chain to the rear axle. now a jeepster (commando) had a t400 but not a cj. Please tell me if I am wrong. now dj, might but a cj?

[CedarGroveCJ5]

I realize this an old thread but i would like to stir it back up. Im currently working on putting a 727 behind my 304 in my 75 cj5. Ive got my driveshafts all made and transfer case adapted, but the only thing holding me up is trying to find the correct flexplate and torque converter for the 304 727 combination. Ive searched several salvage yards with no luck, and if i attempt to order it new the dealers want to give me the same flexplate part number for a 360 and 304, but as we know that is incorrect due to the balancing. Anybody know where to find these parts?

[PavementPounder]

The AMC flexplates used in Jeeps from 80-86 are dual-pattern for both the 998 and 727 - meaning they started with the same blank (same diameter and tooth count) and then balanced them differently for the 258/998's in CJ's and the V8's with the 727 in FSJ's. You can do two things:

1. Buy a flexplate from an 80-86 FSJ with a V8 and 727 and have it rebalanced to the 304.
2. Find an AMC car application that used a 304 and 727, like perhaps a mid-70's Matador.

[jeepster80]

here are two places that sell a flexplate that they list as working with both 304 and 360.

Performance American Style Shopping Cart - Product description
4 Wheel Drive Hardware Search

both places are reputable and should know what they are talking about.
Just curious what people think about it

[dajeeps]

bulltear has the flexplate you need.or at least the web site says.

[jeepster80]

I'll check that out. Thanks dajeeps