As I'm putting the new carb on ( http://www.summitracing.com/parts/SUM-M08750VS/ ), I read in the directions that this carb WILL NOT work with Chrysler overdrive transmissions. So now, I'm trying to figure out if my rig has an overdrive 727. Here's what I do know about it, it's an '87, it doesn't have a lock-up torque converter, there is no O around the D on the gear selector, but it does have a linkage that goes to the transmission that was hooked to the old carb. I never really paid much attention when it was stock if it went into OD when cruising, and I never thought about it until I got the instructions for the carb, since there was no mention of it on Summit's website.

Anyhow, I retro-fitted the the LA throttle cable clamp to fit on the Magnum heads/intake manifold, and I got the throttle cable all hooked up and clamped down. I attempted to hook the linkage that comes from the transmission to the moving linkage on the throttle cable clamp bracket, then I hooked the little flat bar that goes from the moving linkage to the carb. When I did this, it was so tight, and it wouldn't even allow the throttle to open since the slot that the throttle stud slides in on the flat bar that connects the carb to the cable clamp was all the way forward.

Anyone have any ideas on this issue? Do I have overdrive? If not, what would that transmission linkage be for? Thanks!

 

The trans linkage controls the kick down of the trans by monitoring the throttle position. This must be hooked up and adjusted properly. They make carbs that will accept this and they make adaptors for carbs that don't have a provision for this. I would doubt you have OD without a lockup converter.

That is a lot of carb without internal engine mods. IMHO

 

Thanks for the info. Any idea where I might find these adaptors? Apparently this carb is based off an older Holley, and Holley parts work with it. Is there a way to know if it's adjusted properly?

Who said I don't have internal engine mods?

 

Also, I know it's not safe to drive without the kickdown hooked up, thinking that means just driving around in "Drive" gear. What if I manually shift it, and kick it down myself with the gear selector if I need to give it more power. Would that be safe for the transmission? Although I'm not talking about driving it any more than maybe 10 miles or so before I get the bracket fitted on there.

 

As far as internal engine mods, that is the problem of giving advice without knowing everything about the vehicle. You have to make assumptions and add qualifiers to most statements.

The kick down linkage is not really a safety issue (unless you put yourself in a position where you need immediate response to throttle input). It is more of a performance issue. Can you work around it temporarily? Yes, but it will be a pain in the butt.

I haven't worked with that specific carb but if you contact Summit they can help you get the proper adaptors or they have a cable assembly that replaces the OEM linkage and may work for your application. Either way talk to them. Lokar also makes performance kick down cables but they tend to be more expensive.

http://www.summitracing.com/search/?...adapters&dds=1

http://www.lokar.com/product-pgs/thr...c-kd-main.html

 

Ok, so according to this: http://www.moparts.org/Tech/Archive/auto/35.html the kickdown linkage will keep the tranny line pressure up to where it won't cause transmission damage. It says that even if you shift it manually, it will cause your transmission to fail. By the way, that's what I was meaning when I said "safety issue". I should've clarified that. I don't feel like putting in a new transmission.

Here's what I'm thinking, tell me what you think. If I take the stock flat bar that connects to the kickdown linkage, cut it in half, shorten it, and weld some type of threaded adjustment setup (kind of like an adjustable pushrod to get pushrod measurements), and adjust it from there. Because right now, it's way too long.

I found some tips and techniques for how to adjust it here: http://www.forabodiesonly.com/mopar/...ad.php?t=46330 and I'll definitely check the chilton's manual, but that thing has been worthless most of the time.

As far as engine mods go....
5.9 Magnum bored .020 over
Balanced internals
Keith Black hypereutectic pistons
All new bearings
Comp chrome moly pushrods
3000 RPM stall torque converter
Comp .541/.544 280/286 cam
Indy MA-X cylinder heads with 2.02 intake valves
Edlebrock RPM AirGap intake manifold
Summit 750 Vacuum secondary carb
1 5/8" to 3" headers
Mopar Performance lifters
ARP Head bolts
10:1 compression

And I'm sure I'm forgetting some things, but those are the biggies.

 

Trans pressure and its resultant damage to the trans is why I said "temporarily" in answer to your 10 mile limited operation.

Sounds like the carbs throttle shaft is further to the rear on your new setup than on the original. Shortening the slotted rod may work but without seeing the distances and lengths involved I can't say definitively yes or no. If the carb is higher the angles will be different and could cause the linkage/trans to operate out side its range. I would go with the cable system to eliminate any other problems. It is inexpensive (especially considering what you have already spent) and it will be easier. But that is personal preference.

Do you have any idea what HP you are expecting?

I had to type this twice because my computer froze up. I wish I was as good with computers as I am with mechanics.

 

I would expect it to be between 450-500hp at the flywheel. No telling what it'll be at the wheels. I will by dynoing it once it's all tuned correctly.

Looks like there's this kickdown from Bouchillon for $127:
http://bouchillonperformance.com/BPEtkdc.asp
Or the Lokar for $77: http://www.amazon.com/Lokar-KD-2727U.../dp/B005P6NPJC

If I can find a picture of our stock bracket setup, I think I can fab an adjustable linkage that'll work. The throttle cable clamp is in the same location as stock, and that's where the rotating linkage is that connects the kickdown rod from the transmission to the kickdown rod that goes to the carb.

 

Found this little gem on youtube: http://www.youtube.com/watch?v=7lHmn8UUylg Should guide me when setting the kickdown linkage.

 

What he says in the video is good as far as it goes but as he said "the adjustment is done down at the transmission". He did not talk about the adjustment at all.

You are going to be out on the edge of the trannies capability. Hope you have a good trans cooler for that much heat from 500 HP engine.