Engine tranny combo

[blackout]

Can anyone tell me what my transmission options are for a 390.
Thanks
mike

[B.M.B.C]

Hi There
Basically you got a choice depending on you final engine horse power....
Toploader -
Tremec 500/600 tko
T56
Richmond 5sp
Richmond 6sp
T5Z

[RICK LAKE]

blackout Mike I will try and keep it simple,
weight of car?
amount of HP you are looking to get from 390 motor?
rearend ratio?
What are you doing with the car? cruising, autocross, 1/4 mile racing??
Need a rough percentage of car's usage?
size of tires for rearend?
Without this info is a ball park answer.
Would go with a trans ,if stick with a 2.80-2.60 1st gear, depending on rearend ratioand overdrive for cruise with a .87 od again depending on rearend ratio. These numbers would change depending on rear.
Other thing is motor power. If you are building a stock 275 hp motor and the car weight is 4,000 pounds, going to a higher 1st gear will be needed to not have to slip the clutch to move car.
See putting wrong combo's togeather and you have a car that runs poor, can't get out of it's own way, doesn't cruise well, and eat gas at 10mpg.
Bring on some more info. Rick L.

[blackout]

Thanks
I'm thinking around 375 to 425 with a 3.70 rear.
Mike

[mdross1]

I was going to offer a toploader not being used but with a 3:70 cog out back you really should consider an OD trans.My car has 3:70 gear now with a Tremec, for these cars on the street a perfect marriage.Good Luck

[B.M.B.C]

tko600 2.87/.64. Happy days

[blykins]

You really have to pay attention to the whole combination when you pick transmission overdrives. With a rowdier engine, a .64 overdrive will most likely put the cruising rpm in a spot where the cam is not efficient, resulting in the "buck."

If your engine is close to stock or very mild, then you could probably get away with the .64 over the .82. Everything plays a part though....cam, rearend ratio, tire size, you name it.

Most of my Cobra stuff uses a .82 OD if the customer goes with a TKO.

[ERA Chas]

C6 automatic-you didn't exclude it.

[RICK LAKE]

blackout Mike what rearend are you running? Jag, IRS, Solid 8.8??
IMO and I thinks others will agree,
390 stroker to a 445, pocket porting of the heads
hydro roller camshaft in the .550"-.570" lift
What heads are we going with?
10.0 compression with aluminum heads
Most important is a good rocker arm setup Check with Bylkins or KCR for them
HPHV oilpump blueprints from plumper here on CC.
Guess weight on car, 3.70's will be a hand full in low gears
a 3.30-.3.50 would be max rearend. I run 3.31 and may drop to 3.07
trans if running 3.70's first gear will be in the 2.40 or less. you will never use first gear. shift will be quick. I have a 3.05 first and 3.31's shift is in 40ft if the tires don't smoke.
5 spd trans with OD is the way to go. I am not a fan of TKO's I have run richmond 6 spd and now a G-Force 5 spd. Next motor will get a Richmond super street 5 spd with 2.80 first and .87 5th with 3.07 rearend. This is a great match for a torque motor.
As said before, FORGET the HP numbers and look at Torque. Torque moves the car from a stop. There are some great builds of a 390/ 445 by Barry R at Survival motorsports. You have to under stand that the MAX safe rpm on this motor will be 5,800-6,000 rpms because of valve float and lifters pumping up. Large oil pan with min of 7 quarts like a Canton and over fill 1 quart.
If you have a little extra money Have the intake manifold flow check and balanced by Joe Craine. We will match up all the runners to flow (CFM) within 5 cfm of each other. Other wise you have about 5-35 cfm different and poor air direction to some cylinders. Want 8 holes all pulling hard.
With a small camshaft, idle should be just a little shake, 12-14 vacuum at idle and strong off idle running to 5,000 rpms. with an over drive, 135mph is easy to reach, problem is car not becoming an airplane with all the air you are pushing in the front end. Been there not a good feeling. This is a good place to start.

[blackout]

Thanks for all the info. The rear is a 9" and it is not together yet so gear ratio is not a problem to change. If you guys think 3.00 to a 3.50 would be more suitable now would be the time to change it. The car will be used for cruising and most likely no racing.
Mike

[RICK LAKE]

blackout Mike those are MAJOR WORDS.If you are just going to cruise and a little play, The TKO 600 would be ok. This will also give you room to expand the power of the motor down the road. Over build the 9" with 31 spline axles and a good posi rear end. This will last a life time. With 3.50's and over drive, this should be a good combo. Car will run 12's in 1/4 mile and keep up with most street cars. 4 link rear suspension that is adjustable will help with getting power to the ground. Learning how to shift smooth will help the TKO. No full power shifts, No tranny like this even mine that is race.I think you have a good game plan to work with. You have not said alot on the 390 build? Here is something to think about, your 390 parts could be 40 years old and see nothing wrong with them but hundreds of heat cycles. You buy a stroker kit and you get new parts that are balanced and ready to drop in the block. I have a new set of lemans rods I was going to use. They are still 35 years old in the box. The other thing is running BBC rods and bearings you get a wider bearing for the rods. This will spread out the load better than a SB ford windsor bearing on a rotating mass that is 200 grams heavier than SB. Something to think about. This is another reason for running good oil pressure. Down side is checking the gears on the distributor every couple of thousand miles for wear. No bronze gears!!. Good basic oil. 10w-40 or 15-40 will work fine. I do run a bottle of Lucas oil suppliment in my motor. It sticks to all parts inside the motor and helps stop dry starts of the motor unless you add an accusump as a pre oiler 2 quart is good. I run a 3 quart. 80% of motor wear is done during startup. Have to remember that what oil pressure you see on gauge IS NOT what the back of the motor is getting. Anywhere from a 15-40 psi drop depend on clearances in the motor. This is a good start for you. Rick L. P.s. where in NY are you??

[blackout]

Thanks again to all
Rick, I am about 100 miles north of NYC. As far as the car being used fo cuising and no racing I still want a decent amount of power. No exact plans for the engine as of yet as that will have to be done by an engin builder.
Mike

[blykins]

I would be happy to give you a price quote on a complete turn-key, drop-in drivetrain package.....engine, trans, bell, clutch, you name it.

[blackout]

Thanks for the offer, and I would be interested in getting a price for rebuilding the 390 that I have plus a tranny. I will not be needing this for at least 4 months
Thanks
Mike

[blykins]

That's sort of the nature of the game for Cobra builders/buyers. Lots of guys start researching many months ahead of time, which is a wise thing to do.

I'd be happy to help if you want to PM me or email me a list of what you would like/need.