I'm new to this board. But hope you don't mind helping out a "newbie".

I am going to be looking at a '64 SS that has been modified with a 454 HO crate motor, a B&M Turbo 400 w/ 3500 stall converter and it has a Ford 9" rear end with 3:70 (+/-) gears. This according to current owner.

I was wondering about this set-up as regards overall operation (any problems with it,etc?).

One concern I had read here was about the frame cracking in some cases (not specific to a big block installation, necessarily).

Since the '65's used the convertible frame for those big blocks (that's what I read anyway)I was concerned this model ('64 true SS) might be susceptible to frame damage (too much torque?).

In general, is this conversion common?

Any thoughts or help appreciated.

Regards, Mark

Mark,welcome to TC graemlins/thumbsup.gif

Sounds like a fun car,with a very streetable drivetrain.

I know of several 64-65's running around with big blocks with no major mods to the chassis.

Personally would prefer a converter with about 2400 stall instead of the 3500 converter with that motor, but that is an easy fix.

I was wondering about the stall speed. I'm not that familiar with performance based auto trans.

If this is a stock 454 crate motor it's peak torque is around 3200 rpm I think. Max hp around 5000rpm or so. GM's #'s are 425 hp & 500 trq (gross at flywheel I suppose).

So, based on all this and the rear gear ratio (3:70's) the 3500 stall speed is too high correct?

One more trans question. What is meant by a locking type converter and would that be recommened in this application?

Thanks for the responses.

Regards, Mark

Welcome. Your newbie questions are of interest to a lot of people, so ask with abandon.

When these cars were new and 4 speed trannys ruled there were a lot of wheel hop issues. The bouncing rear axle from wheel hop was what cracked frames, not the power level. Fortunately the factory came out with the fix to resist cracking frames, first for the GTO, then used on the other A body cars: triangulation bars that connected the frame mounting points of the rear upper and lower control arms. Of course items like boxed lower rear control arms and good control arm bushings are important too.

Yes, the Z-16 cars used the boxed convertible frame. Nice touch, but not an absolute need. Plenty of Chevelles on this board using regular frames in cars a lot quicker than the factory Z-16.

Nothing wrong with a 3,500 stall converter, I've run deeper stall on the street.

Remembering that you are looking at a 40 year old car that is modified beyond factory specs there is no easy way to predict trouble spots. If you are unsure of how to inspect the car's mechanical condition then it is best to hire a mechanic to do that inspection. Either this car has been put together right or it is a fright pig, a good inspection should reveal most details.

I can't speak as to how common a big block '64/'65 is - but I can tell you they are plenty of fun smile.gif

Thomas

Thanks Thomas, that's good detailed info I needed to know.

When I look at it I will look to those frame areas and rear suspension set up in general. The fact that a previous owner put in a Ford 9" may be a sign that other rear suspension enhancements were also done at that time.

Car is in another city in Florida so it may be a couple weeks before I see it.

It was a Calif car, made in L.A. according to the VIN. Present owner bought it from a guy in Commerce,Ca.(pretty sure I got the city right)who had done all the mods I mentioned. So, no rust is a real draw for me as well as the engine size.

So, you wouldn't see a need to switch to a lower stall converter in a mild cammed big block?

Thanks!

Regards, Mark

The only way I could reccomend a cam or converter change is if I drove it and didn't like it. I know that even with a 3,500 stall it will start moving well before 3,500 rpm. All the higher stall does is allow the engine to more quickly flash up to that part of the power band when the right pedal is stomped!

Thomas

Thomas, thanks for the reply.

So, there would not be a concern of heat buid-up in the tranny during normal cruise situations (say between 2000 to 3000 rpm's)?

Does the stall converter essentially allow the trans to "slip" until that stall speed is reached? Is this where the possibility of heat build up that I've read about comes from?

Many thanks for the info!

Regards, Mark

Mark, I've run up to 4,200 stall on the street with no trans overheating - I had a trans temp guage in the pan to verify. I used a motorhome 33,000 gvw trans cooler, that was it. If your converter was a cheapie that gained stall by just bending the fins instead of proper innards, then you would have trans overheating issues.

Check the trans fluid for any signs of decay.

With the exception of a lockup converter in locked mode, all automatic transmission/converters "slip". The same thing you call slip is part of what can help your torque converter transmit more torque output than input for a brief moment - all the better to launch you.

Thomas

O K I think I've got it.

Thanks for taking the time to explain this to me!

Mark