hey whats up guys i just got done converting my truck to diesel i had a 454 that loved gas but now it wont shift it has th400 in it. i dont have a vacum pump i was wondering if the would shift with out it. either than that the conversion went perfectly the 6.2 starts rite up

NO. Th400 relies on vacuum to shift. It will shift at redline which is about 4000rpm or so. Diesel has an open air supply so it doesn't create vacuum on it's own. It need the pump. Wheres the pump from the 6.2

it didnt come with one the other had a manuel 3speed.

is it better to get a vacum pump from a 6.5 thats belt driven or the one that looks like a distributor?

Depends on if you have the serp setup or if not whether you have the room on the pulley for another belt. Even if you use the belt diven one you need something in the distributor area to drive the oil pump. If you don't have anything in there stop driving your truck 'cause the vac pump has a shaft that goes down and turns the oil pump. Seems like my vote is for gear driven over belt driven. If you can't find one that produces enough vac (20+ " at idle) the pod (circlular part) can be transfered from belt driven style to gear driven style (with a minor amount of force to push it past the intake)

it has the dummy shaft in there if it had a 3 speed behind it before.

I thought they all had vac pumps in case you had cruise or something about HVAC

ya i have a dumby shaft in it rite now. Are the vacum pumps rebuildable or do i need to find a new one?

what do you think my top speed would be with that th400 tranny an a 4.10 rearend? i was wondering since i have less rpms to use now.

top speed is probably 75 mph. but that would be redlining the ol girl i think. keep it around 55-60 for best fuel milage.

that will ok for towin. has anyone tried one of those gearvendor things? are the worth the money? how do you hook up a tach with out a coil??

gearvendors are over priced and tend to burn up after some miles.

I have the same trans and diff as you and I can bury the needle but she's complaining after a short while. My usual cruising speed is 65mph but I can maintain 70-75 without issue. I don't get great mileage at that speed but 17mpg in a full size truck isn't too bad.
No I don't think the pumps are repairable. I'd try a wreckers for a stem from a 6.2 and a pod for a 6.5 (only cause they're newer and more likely to give good vac)

i didnt see what you said happened to your old vac. pump..do you have a 6.5 in its place or something..i lucked out and got a brand new vac pump at a swap meet for 1.00 the guy had no idea what it was...:)..i have i think 4 laying around..most need em for heater controls..or cruise..even if you have a 700r

He had a standard and a blank stem for the oil pump

ohh ok i see..well he will need a vacuum switch for the i/p also. i take it

the 6.5 vacuum pod attatches to the body with 4 bolts. the 6.2 pod only uses 2.

attached mine with the two bolts and then I think Iput the other 2 in as dummies. I have no problem with mine and it produces about 25" at idle andgoes up a bit with throttle.

thanks for all the info guys, i was thinking i wouldnt be able to break 60mph with my th400. Do u have any ideas how i can hook my tach up its the stock gasser tach? Do the factory diesels come wit factory tachs?

If you don't have a vac pump yet and want a tach you can buy a vac pump with a speed sensor on top. They're a little pricey but they it gets two birds stoned at once. Not real sure of how it hooks up tho.