What transmission behind a big block

[patmckinneyracing]

I've decided that when I do the second restoration on my 80 malibu, I'm going to be doing a police interceptor theme. I'm learning right now from my current set up that I wish I made different decisions. Right now I have my 350 probably putting out about 350-400hp, TH350 transmission with the b&m shift kit, and I've swapped the rear end twice so far. Currently I'm in college so I swapped out my 3.73 ss rear end for an elki 2.41 rear end in an attempt to get better gas and for better driveability. The main problem I had with the 3.73 gears was on the highway when I was at 70mph and turning 4-4500 rpm making for an uncomfortable ride.

My guess for the best solution to this problem was to get a transmission with an overdrive so I'm not having to swap out rear ends and I could keep my 3.73. If I decide to go with a big block (more than likely I will), will an overdrive transmission mount up behind a big block or am I limited to the TH400? And do all 700r4 and 200r4 trannies have an overdrive?

The plan is to go with a supercharged 396 or 454 big block (If I'm lucky a 427). Is an overdrive transmission able to hold up to the power and torque of a blown big block?

 

[jrm81bu]

Re: Discussing future drive train options

If I decide to go with a big block (more than likely I will), will an overdrive transmission mount up behind a big block?

Yes

And do all 700r4 and 200r4 trannies have an overdrive?

Yes

Is an overdrive transmission able to hold up to the power and torque of a blown big block?

Only if it has been built up right. You might want to look at Bowtieoverdrives or the company that Art Carr is making transmission's for now(can't remember the name of the company right now) might be called Califonia Performance Transmission.

 

[patmckinneyracing]

How do you like your set up cause I know your running pretty much the same thing I'm thinking of just a sbc instead of a bbc.

Another question: I need to figure out the differences in superchargers. I know there's the design that looks like a turbo style and then you have the 6:71 and 8:71 blowers going through the hood. Is the blower considered a type of supercharger? Just curious if there's specific names besides "supercharger".

 

[jrm81bu]

I like my set-up(might be up for sale though), but if I was starting from scratch, I might just stay with a 2004r(less to modify to make it fit).

The 6-71's, 8-71's, etc., and even the small ones like mine 142cid, are roots style. The ones that look like a turbo, vortech, procharger, etc., are centrifugals.

 

[patmckinneyracing]

What all did you have to modify? I thought the only thing was to have a shorter driveshaft made to compensate for the longer transmission. Idk how good the 200r4 is as far as quality but it seems to be popular with a lot of g body guys.

 

[TURNA]

Just keep in mind a built right 2004r or 700r4 for a big block is going to run you around 2 grand. Plus the converter.

2004r's are usually a little higher priced than 700r4's

Then regardless of what the 7.5 inch rear came out of you can kiss it goodbye.

Time to upgrade to at the very least an 8.5.

Superchargered big block ...add a couple of more bucks to the cost of the transmission.

 

[v8power]

Only if it has been built up right. You might want to look at Bowtieoverdrives or the company that Art Carr is making transmission's for now(can't remember the name of the company right now) might be called Califonia Performance Transmission

.

your thinking of gear vendors O.D. set up. a bit pricey but we have ran them on 800hp cars and never had any issues.

 

[patmckinneyracing]

I know overall the engine will definately set me back, that's a given. What is the main difference between the 2004r and 700r4? As far as the rear end, isn't it almost impossible to find an 8.5 anymore? I know there's conversions to fit a 12 bolt or even the ford 9 inch kits. I can hear the register bell now.

 

[TURNA]

8.5 rears are out there

There are even a couple for sale on here.

Or you can buy a bolt in 9 inch.


You thought it was an uncomftable ride before?

You cut corners in the wrong places to save a few bucks and you wont have a ride.

That thing will be riding you as you push it off to the side of the road.

No Police "interceptor" (FORD) has a supercharger under the hood.

So I am asuming you are thinking MAD MAX when you say that??

If you are thinking MAD MAX then not sure if you know that superchargers can not be turned on and off.

If you are pushing 350-400 HP now how much more do you want on the street?

I think you would be happy with just saving up your money, getting a 700r4 or 2004r and reinstalling your 3:73's

I'm not trying to sound like a dick, but you need to know your budget and your limits.

Most guys in college don't have alot a cash to spend, or you might have the $$ to blow, I don't know.

But if you installed a 2.41 rear to save gas then I am not sure why you want the big block with a supercharger.

And yes I know it is cool and awesome.....But cool and awesome cost $$$$$$$$$$$$$$$$$$$$$$$$ and this $$$$$$$$$

 

[drogg1]

The 2004r has gear ratios of: 2.74:1, 1.57:1, 1.0:1, 0.67:1, 2.07:1(Reverse). The gear ratios in the 700R4 are: 3.06:1, 1.63:1, 1.0:1, 0.70:1, 2.29:1(Reverse). Fit wise, The 2004r will bolt in to any car originally equipped with a TH350 with slight crossmember modification due to the fact that the transmission mount is located some 6 inches farther rearward. The use of a TH400 crossmember has been known to come to close fitting. Also, one trick is to cut the mount of a standard TH350 crossmember and weld it back on to the trailing side of the crossmember. Additionally, some companies sell new crossmembers for this particular swap.

For the 8.5" GN rear- Perservere and keep looking. I am no where near to having enough money to swap mine and I find them fairly regularly on ebay and I even believe if you search a little bit that there may be some rearends for sale on this forum. I fairly consistently see them for around $800 dollars so be prepared to spend at least that not to mention what I would imagine to be horrendous shipping costs.

Just thought I'd add the two cents worth of information I know