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View Full Version : What gearbox between a chevy 350/430HP and a jag diff 3.31??



drimman
15-02-05, 08:46 PM
:confused:

Can anyone tell me what gearbox will be proper between a Chevy 350/430HP and a Jag diff 3.31?? I'm thinking about Getrag, or Tremec. Any advice on type , where to get it low priced??

Thanks for the effort!!:thumb: :thumb:

Grease Monkey
16-02-05, 07:45 AM
As my sig says, i'm running an Edlebrocked SBC 350 to a Jag 3.54PL. I'm running a Tremec 3550 TKO with uprated clutch.

Whole package including flywheel, clutch friction plate, pressure plate, bellhousing, gearbox, delivery etc came to about 2300 from Brian at Repower/ Roadcraft UK

Not sure what the final drive ratios are going to be yet, but it was what was recommended.

drimman
16-02-05, 06:26 PM
Thanks Adrian, that gives me something to work on. altough i'm thinking about a diff with 3.31 or 3.07, this is to give it more acceleration power.

Rene:D

Chimeara
16-02-05, 07:59 PM
Hi, Im running a 350sbc upgraded to 350BHP and this also is using a Tremec 3550 box. My diff is a 3.54 powerlok. The gearbox was correctly supplied at the same time as the engine from british american engines call Ian Briggs he is a good chap and is always willing to give free advise

Anthony

madjohnny
16-02-05, 11:19 PM
I too am running a 350 SBC RPM performer (supposidly 420BHP) with Tremec 3550 which Bri at Repower said is more than capable of taking that kind of power/torque. probably if you are thinking of doing some track days it maybe worth upgrading to something a little stronger ie. TKO 500/600.

adricar2
16-02-05, 11:19 PM
i am selling the tko500 at the moment for 1360 inc


www.americanv8engines.co.uk

adrian

mikey
17-02-05, 07:39 AM
If you are running a performer RPM in a 350 forget the 420 HP unless you are up at 7000RPM and have done significant work to the engine you will probably be anywhere between 350 and 375 BHP and if well prepared (zero deck etc etc around 390 BHP (cost me a fortune to get to 395 BHP in my last car with this set up).

Go for the Tremec that gives the acceleration (in my opinion). The thing I found with the RPM cam was it was geared very much towards acceleration and does little for traffic or touring. As the RPM set up dosent do much for Torque increase, particularly at low end where it hurts, the 500 TKO sounds a good deal should easily cater for the track day set up I would have tought.

Mike.

kdavies3
17-02-05, 09:51 AM
I'm running a Tremec TKO 5 speed behind my 383 stroker at 450 bhp (according to the builder).
I'm also running a 3.07 diff. I find it great for cruising and general blasting but on a track day a 3.54 would be more fun. :thumb:
Overall 3.31 is absolutely ideal I think you made a good choice there.:D

crendonman
17-02-05, 10:26 AM
I'm using a Tremec TKO II 5 speed with a 3.31 in conjunction with a ~350bhp Cleveland.

No problems from where I stand! :thumb:

kdavies3
17-02-05, 01:31 PM
I can vouch for David's Crendon being a real thrill ride. :thumb::thumb:

YEEEHAAAH!!

Grease Monkey
17-02-05, 03:55 PM
Thanks Adrian, that gives me something to work on. altough i'm thinking about a diff with 3.31 or 3.07, this is to give it more acceleration power.

Rene:D

I think you'll find a 3.31 or 3.07 will have less acceleration than a 3.54

The lower the number the slower the acceleration, but the higher the top speed.

madjohnny
17-02-05, 04:38 PM
Mike, realise these figures are only thrown about by the builders but you've gotta quote something! As for the lack of driveability I'm only gonna bring mine out on sunny days for a scream around, so the fact the engines a bit of a screamer on all accounts suits me fine ( along with the lumpy tickover).:D :D

mylesdw
17-02-05, 05:39 PM
3.31 is definitely a good compromise when running a 5 speed with fairly standard overdrive on 5th (around 0.8:1). If you end up with any higher ratio on 5th (0.68:1 say) then the 3.54 diff is the one to go for. I can't see the 3.07 diff being any use unless you are running a 4 speed or you do a lot of motorway work.

clive a brown
17-02-05, 06:22 PM
Here's my 3d worth.


Chevy 350 ZZ4 rated 355 bhp and 410 ft/lb

with a tremec 3550 and a powerloc 3.07

I find that the long torque spread from 1500 to 5500 means that the fairly long gears work very well.

If your set up gives you a peaker torque spread it wont suit

The 5th gear lets me get a good mpg when on the motorways
Clive:)

mikey
17-02-05, 08:27 PM
Mike, realise these figures are only thrown about by the builders but you've gotta quote something! As for the lack of driveability I'm only gonna bring mine out on sunny days for a scream around, so the fact the engines a bit of a screamer on all accounts suits me fine ( along with the lumpy tickover).:D :D

What I was trying to say was it comes in at the top end so the gearbox will be fine as the killer is bottom end torque when under hard acceleration with maximum grip the greatest stress is put on the gearbox.

Just a thought, if you havent got the cam chain etc installed it may be worth going for a hex adjust set as I always suspected retarding the cam by 6 to 8 degrees on the Rpm Would make the world of difference. I,ve got the system on mine at present although I havent had it on the road yet - still a couple of months away.

Have Fun

Mike.

jonbillings
18-02-05, 06:11 AM
For what it is worth I have a 350 SBC with a Muncie 4 speed, currently a 2.88 which is excellent on the motorway but a little slow off the mark (but great through the gears). I have a 3.54 which I was going to swap - but fear this may go to the opposite on a 4 speed?

Might be willing to swap either for a better ratio?

Is it possible to swap cogs/gear ratios in the box - ie the 1st or last to get a better mix?

Jon

snakebite
19-02-05, 11:55 AM
Originally had a getrag 5 -speed with a 3.54 diff, great accelaration, cruising at 85-90 revs at 3000, a bit high. Fitted a T600 6 -speed, best of all worlds. Still great accelaration and with the 6th gear at 0.62 cruisin at 85-90 approx 2300 revs. As sig the bee's b******s :thumb:

drimman
19-02-05, 05:48 PM
I must say that you all give good advice and i'm sure now that there is a lot of knowledge and experience on this site that will guide me through the building proces of my AK.
I'm sure the Tremec and then Getrag are nice gearboxes, but what about the box from the Toyota Supra, the W154!! It seems this one can handle a lot of torque also.
Any experiences here?


Drimman

mikey
20-02-05, 09:27 AM
I ran the Supra gearbox on my last motor before getting a TKO. It was fine until I put my foot down in 4th on a hill. It stripped the first motion shaft.

If you always remember not to but it in low gear when there is a lot of resistance - hill etc its a great gearbox.

If you do go that route - look for somebody that imports Toyota parts. The supra turbo gearbox is dead cheap with little mileage on it if they import secondhand parts. This is because the Japs tend to change, scrap or demolish theie cars well before we do. The gearbox from the Jap Litace(non export is stronger than the turbo(so they told me) and has a better ratio for acceleration if you prefer that. I believe the spline that accepts the yolk is stronger as basically it is also a van gearbox.

Mike



I tried to find the address of the guy I got mine from in 1995, but its gone amiss. I will keep looking for you.
Mike.

drimman
20-02-05, 10:05 AM
Hi Mike,


I found an adress in the UK that supplies the Toyota gearboxes. It's at: http://www.classicconversions.co.uk
I asked them to give me advice on a gearbox, but no response until today.
I know the W 154 here in Holland and we have those Toyota Vans here also, but i can not imagine that they have better gearboxes, i will try to get one from the scrapyart to check it.
How many Torque did your engine give? Maybe you know the website from the engine supplier Fastco in the US?

Thanks for the effort


Rene