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Discussion Starter · #1 ·
well i finally got the 460 mach fired back up and running again but its no in utah anymore and now in california.

at first it seemed as if my tranny wasn't shifting into3rd gear, because at 60mph on the highway i'm running 3500rpms and almost 4500rpms going 70mph. that seems like 2nd gear numbers at those speeds. i made sure if its shifting by manually shifting it and it is shifting TWICE. however the rpms is still too high in 3rd gear. with my gears and tire size i should be 3300rpms going 70mph.

so how all of a sudden will my rpms be way up higher going the same speeds as before? however i did get a kickdown rod off of a 75 f350 and tried it and played with it but it didn't work cuz the intake is too high for the kickdown to fit the carb. do you think it could be stuck in passing gear?

or do you think there can be something else wrong?
 

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Did a manifold swap on my '68 one time way back
in '79 and forgot to re-hook up the vacuum line to the
trans. As you can imagine, it wouldn't shift into
3rd gear......
Just throwing something out, don't know if it helps
or not.
 

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Discussion Starter · #4 ·
a friend of mine is saying maybe what i got is a heavy pulling truck c6 and that doesn't have a 1 to 1 ratio in 3rd. but it would have to be a huge difference from 3350 at 70 1 to 1 to 4500rpms at 70 with whatever it is.

he also thinks its a heavy pulling truck c6 because there is a funky pan on it that is really deep in the middle and its shaped like a upside down hill from the side.

any thoughts?
 

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All c-6's I've ever seen are 1:1 3rd. The only difference is the wide ratio c-6, with a lower 1st and second.
 

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If you KNOW your rear gears Olie, and when you put it in 1st and take off it stays there and then you put it in second and it shifts and stay's there then put it in Drive and feel if it shifts into drive. If it does then the tranny may have been played with or you are wrong about your rear gears....

Are you here in Ca. yet Olie?

FE
 

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Sounds like your convertor might be slipping.

If its a high stall convertor that will cause you to have more slippage on the highway, but i cant imagine like that.

Also are you sure of the rear?? If so use one of the many calculators on the net to see what you should be running.

Heres one of many to choose from
http://www.csgnetwork.com/speedcalc.html
good luck
 

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Discussion Starter · #8 ·
i don't have too high of a stall, its a 2500 stall and my cam recommends a 2400 stall. i am sure of the rearend i got, i picked up a 3.89 gear 3rd member when i purchased it. i made sure also, i turned my drive line a few times and counted how many times it took to spin the wheel once.

well maybe the rearend gear fairy and changed it to 4.30's or something. i was mistaken with the rpm's i'm reving about 4250 on the highway to mainain 70mph. but still thats 900rpm difference from what it should be.

however, i got my shifter situation fixed and i'm manually shifting it and its definetly shifting. definetly 2 shifts away from 1st.

can i converter be slipping still even when its spinnning around 3000-4500rpms?
 

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Discussion Starter · #9 ·
i just checked it out on a calc, with 28 inch tires going 70mph @ 4200rpms, i'd have to have a 4.90 gear.

no way in hell i have a 4.90 gear!!!!!

sounds like the HUGHES converter is slipping more likely?
 
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