Replacing 6 cylinder with V8 and super T-10

[thunder71]

I have pulled my old 250 and 3 speed transmission and have a 350 with a super T-10 out of a 1971 camaro That I am going to install and was wondering about the stock crossmember for the 3 speed. Does it need to come out ? I have a crossmember from the second gen camaro I am hoping I can make work. Will the stock one be in the way? Do you think the 4 speed shifter will work with my bench seat ? I'm getting close to being ready to slip it in and curious about the crossmember.

[padresag]

3 speed trans did not have a crossmember and did not require one. neither does the t10.
it will work quite well suspended off the bellhousing
ron

[thunder71]

That is the crossmember I am talking about the one at the old bell housing...the bell housing I will be using is the aluminum one from the camaro and I will install a crossmember at the tail of the T-10...or should I use the old bell ?

[padresag]

I would just use the old bellhousing. either way works though. with old b/h though saves tinkering with remounting emerg brake stuff
ron

[andyh1956]

What ratio is your transmission?

[thunder71]

It is a 2.64 first gear ratio...the rear is a 3.73 posi...I'm worried about hanging the transmission off the bell housing...the motor is not stock and I will add more power as time goes by.

[66Submarine]

Originally Posted by thunder71

It is a 2.64 first gear ratio...the rear is a 3.73 posi...I'm worried about hanging the transmission off the bell housing...the motor is not stock and I will add more power as time goes by.

I'm assuming your engine mods are aimed at producing rotational force, right? Just use the existing bellhousing.

With the OE setup the bellhousing is very stoutly mounted to the crossmember. With the tailshaft mount/crossmember you are just trying to tear the rubber engine mounts apart (which actually is kind of a concern). It's your truck, but IMO you will just be wasting a lot of time cobbling up an inferior setup with the camaro stuff. If you are really hell-bent on it I'd at least recommend you use the later engine mounts.

[thunder71]

So why is it all cars have a rear crossmember and the trans bolts to it? I have the polyurethane motor mounts to fit the truck along with the transmission mount...I had a 66 c10 short bed years ago someone installed a turbo 350 and it had the crossmember at the tail like normal cars do and if I remember they torched the factory bell housing member out...so if I bolt it to the factory bell housing mounts and run the $hit out of it with 4-500 hp it will hold up? I have a small blower and a sbc 434 for the future.

[padresag]

hey, you can do what ever you want to do, so do it. you asked a question and you got answers that you do not like. why and when they changed to the rear trans mount was with the advent of the aluminum automatic trans.
you will rip gears apart before you ever bother a bellhouse only mounted trans. a lot of hd truck trans all hang off the b/housing
ron

[thunder71]

It's not that I don't like the answers I'm getting just trying to understand and get it right...the answers are good and hanging the trans don't sound bad...the stock trans is iron and the T-10 is aluminum ...so poly mounts will work? Motor and bell.

[66Submarine]

Originally Posted by thunder71

So why is it all cars have a rear crossmember and the trans bolts to it? I have the polyurethane motor mounts to fit the truck along with the transmission mount...I had a 66 c10 short bed years ago someone installed a turbo 350 and it had the crossmember at the tail like normal cars do and if I remember they torched the factory bell housing member out...so if I bolt it to the factory bell housing mounts and run the $hit out of it with 4-500 hp it will hold up? I have a small blower and a sbc 434 for the future.

Not all cars, actually. The auto trans stuff mounts at the tailshaft, just the nature of it. Are they the interlocking type of mounts? The ones I'm referring to are the later '73-'87 type.

You can break anything and IMO if you look for weak points you will probably find them somewhere. The OE setup is basically a mid plate mount. I'd personally much rather have it than the auto style.

That being said, it's still just an iron bellhousing. What if while you "run the $hit out of it with 4-500 hp" you blow the clutch up? I don't know how you are going to drive.

If you are really wanting to go full-stop stupid with a blown 434 I'd suggest all good stuff like an explosion-proof bellhousing, steel flywheel, good clutch, etc. And then you still have the transmission itself. And the rest of the driveline.

For the current application I'd just leave it. It's already in there and has worked for countless others in the last half a century.

YMMV

[LostMy65]

Here you go :
Early Classic Enterprises has a 63-72 kit.
http://www.earlyclassic.com/catalog....gory=New+Items and look for the kit on this page, or search for part number #911-GenIII.

[66Submarine]

Originally Posted by thunder71

It's not that I don't like the answers I'm getting just trying to understand and get it right...the answers are good and hanging the trans don't sound bad...the stock trans is iron and the T-10 is aluminum ...so poly mounts will work? Motor and bell.

As an example, the guy that owned my father's '66 in the past managed to notably twist the splines of the two-piece driveshaft with a M20 Muncie mounted as described. (And this was certainly not with 500HP, FWIW.)

Are the mounts the OE type? If so really anything should work fine IMO. It's only if you use the tailshaft trans mount that I'd worry about the engine mounts themselves, since they are then asked to keep everything from rotating (with the OE setup the bellhousing is bolted to the crossmember like a mid plate).

[66Submarine]

Originally Posted by LostMy65

Here you go :
Early Classic Enterprises has a 63-72 kit.
http://www.earlyclassic.com/catalog....gory=New+Items and look for the kit on this page, or search for part number #911-GenIII.

BTW, these that LostMy65 posted are the 73-87 style mentioned.

[LostMy65]

Here's an interesting related thread about your concern :
http://67-72chevytrucks.com/vboard/s...d.php?t=147974

[66Submarine]

Originally Posted by LostMy65

Here's an interesting related thread about your concern :
http://67-72chevytrucks.com/vboard/s...d.php?t=147974

Yep, that's it. IIRC my father had a '64 Impala do it to him once (might have been another car).

[andyh1956]

The tri-five cars had the clutch housing mounted to the cross member like the trucks with a little different mount. It was common to keep the stock mounts & add a trans mount between the frame on big block installs. I don't know if I'd worry too much about how it's mounted, 500 hp on a T-10 is gonna give you enough of other things to keep fixed before the mounts give you trouble...

[Mackie]

The other benefit to the old cast iron BH is a BH mount starter which eliminates the starter shimming dilemma of block mt. starters.

[thunder71]

So your saying I will need a new starter? Has anybody here used a rear transmission crossmember ever? Why would this be the bad or wrong way to do this swap...lets here from some of you that have done this and what did you have to do or modify for this swap...I am a welder fabricator and do it for a living so fab work is no big deal...I am just building me a hot rod to go with my others...not a race truck but street rod...this is for racing

[thunder71]

Me and my son have building the 71z since 1996 ...the truck is just my next project that I am transforming into what I want my toy to be...if I break parts I will fix them as I need to...m22 could be had...got my grandson helping me on this project...he is 12 and we will be building his 69 c10 short stepper soon.

[thunder71]

So I like some power and 3 pedals ...LT3 with 6 speed...anyone done this swap yet?

[padresag]

this does't make sense, ".not a race truck but street rod...this is for racing"
there are 2 different ring gear. you just have to make sure which you are using with which starter
the earlier 3 point mounting was bad for popping that left side eng mount, esp wity automatics. 4 point not so much as you had that bolt running thru the cross member into the bottom of the cast iron bellhousing.
the early hotrods; mainly old fords usually always used the early ford motor mount pad an most engine installations as it had a bolt going up thru it.
in the chev eng mounts they are rubber bonded to steel
chev I6 from 32 -62 used a 3 point mounting and never had many problems. 1 under the timing cover and 1 on each side of the bell housing
I can remember years ago with 58/9 tbirds with 332/352 engs with a/ts you could go out when roadtesting and pop those left hand mounts at will
if you are are only going to drive it 1/8 or 1/4 mi at a time then you can solid mount it but for everyday that could become annoying.
there was a reason why they mounted a l/side safety chain or cable to the left side of 3 point mounted engines. later mounting is better
ron

[thunder71]

[QUOTE=padresag;7694719]this does't make sense, ".not a race truck but street rod...this is for racing"

I'm thinking you did not see the picture I posted after I said that..my 1971 Z28...I already have the polyurethane front motor mounts to fit my truck mount...this 66 c10 is a street machine and has tags and might see some 1/8 mile runs but the Z was built for the purpose of the drag strip...

[Mackie]

No you don't need to change starters. You can use a modern block mt. with the iron BH but the flywheel needs to match the starter type as has been said.

[andyh1956]

OK I may answer your questions as I see them.
Advantages to iron clutch housing-
Four mounts instead of three- WAY stronger
Stronger starter- nose is iron
11" clutch flywheel
bottom is open, change clutch without having to remove clutch housing & support engine

Disadvantages-
Anybody think of any?