[1970 GMuscle]

I think you are putting too much effort into forcing the use of 2.56
How about 3.08 or at least 2.73, I had them in my Buick and it was fun the long shifts.
Make sure your t350 is bullet proof w all that torque. I expired a few. And get the right convertor
You want to run w the FAST guys. Their cars are on point.
Do it right and get in the mix.
Good luck man. Cool project.

 

[Dragginwagon467]

I think you are putting too much effort into forcing the use of 2.56
How about 3.08 or at least 2.73, I had them in my Buick and it was fun the long shifts.
Make sure your t350 is bullet proof w all that torque. I expired a few. And get the right convertor
You want to run w the FAST guys. Their cars are on point.
Do it right and get in the mix.
Good luck man. Cool project.

I like the long shifts I have now. 1st gear goes 60-65 now.

Eventually, I could see re-gearing to 3.31 or 3.55 and adding a real converter, but then my goal wouldn’t be 11s.

 

[PileDriver]

A converter is usually FAR more important than gears anyway. The thread title should be "run 11s with a 50 year old stock TH350 converter!" Heh!

 

[blue_69_malibu]

I like the long shifts I have now. 1st gear goes 60-65 now.

Eventually, I could see re-gearing to 3.31 or 3.55 and adding a real converter, but then my goal wouldn’t be 11s.

This past November or so, the topic came up with my trophy laden drag racing buddies as to whether one of Mark's 600/600 468s would put me in to the 10.90s, driving to and from the track on drag radials.
The unscientific consensus was.....no....not with my 3.36 rear gears.
I'm a full weight '69 Malibu...so I think I'm several hundred pounds lighter than you.....FWIW.
Will be fun to find out, though.

 

[nashville beth]

SMI Carburetors published a nice article on modifying quadrajets for racing.
If you can start with an Edelbrock 1910 quadrajet, it has a .149" inlet and the idle system is set up for a Big Block making 500+ hp; no mods needed.
It's also rated 850 cfm. I picked one up for $350 in excellent condition and Cliff Ruggles supplied a custom kit for it based on my cam and heads.

 

[Dragginwagon467]

This past November or so, the topic came up with my trophy laden drag racing buddies as to whether one of Mark's 600/600 468s would put me in to the 10.90s, driving to and from the track on drag radials.
The unscientific consensus was.....no....not with my 3.36 rear gears.
I'm a full weight '69 Malibu...so I think I'm several hundred pounds lighter than you.....FWIW.
Will be fun to find out, though.

With the converter, maybe?

Hopefully I’ll get to test the 511 with better gears and converter in the future. Right now it’s 2.56 gears and original 1970 converter.

 

[Dragginwagon467]

A converter is usually FAR more important than gears anyway. The thread title should be "run 11s with a 50 year old stock TH350 converter!" Heh!

Up to a point, I suppose you’re right, but the reality is most things that increase the number of bangs per 1/4 mile will improve your ET, assuming you have traction, and are still making power out the back door.

I remember when one of the magazines did a test on a mild small block Chevy nova and went through the gears of 3.00, 3.50, 4.10 and a 4.56 I think, and three converters. Their conclusion was that as long as you had either the gear or the converter correct it really didn’t matter. They found that the engine didn’t have enough high-end horsepower to support the 4.56 gears.

 

[68Chevele]

I have had 2 cars in the past with 2.56 gears, the '70 Chevelle was a dog out of the hole with the stock converter but was a car killer from a 40 mph roll. The other car a '71 Nova had an 11" TCI street fighter converter and was a screamer for what it was out of the hole. Even though the Nova was a little lighter it got the job done better then the Chevelle. I switched to 3.31's in the Chevelle and it really woke that car up. I switched the 2.56's in the Nova to a 3.42 rear axle and did not notice much difference in performance. Both cars were mild SBC's.

 

[gnicholson]

This past November or so, the topic came up with my trophy laden drag racing buddies as to whether one of Mark's 600/600 468s would put me in to the 10.90s, driving to and from the track on drag radials.
The unscientific consensus was.....no....not with my 3.36 rear gears.
I'm a full weight '69 Malibu...so I think I'm several hundred pounds lighter than you.....FWIW.
Will be fun to find out, though.

I would bet money it will if the chassis is working and the converter and tuning are good

 

[Dragginwagon467]

I have had 2 cars in the past with 2.56 gears, the '70 Chevelle was a dog out of the hole with the stock converter but was a car killer from a 40 mph roll. The other car a '71 Nova had an 11" TCI street fighter converter and was a screamer for what it was out of the hole. Even though the Nova was a little lighter it got the job done better then the Chevelle. I switched to 3.31's in the Chevelle and it really woke that car up. I switched the 2.56's in the Nova to a 3.42 rear axle and did not notice much difference in performance. Both cars were mild SBC's.

You’re experience with the Nova is kind of how I feel about my Monte now...the engine makes enough torque to make the 2.56 feel like a small block with 3.42 gears. Street driving couldn’t hardly be more enjoyable. I’m excited to see how much different a 496 or Mark’s 511 act compare to my current 467.

The difference between a 355 and a 383 is readily apparent, but that difference is a larger percent increase than going from a 467-496. Comparing the change from a 355 to 388 to a 467-511 is more accurate. In this case, the 511 is also built by a pro...so the difference will be multiplied.

 

[427L88]

It'll feel like you just put a bigger DIESEL under the hood, that's how!

 

[blue_69_malibu]

I would bet money it will if the chassis is working and the converter and tuning are good

Don't tell me that. You'll make me buy something.
Obviously, I wouldn't know until I tried. That said, I'm currently making somewhere between 470-480 Gross HP and TQ....and running 12.2x to 12.3x in the heat and 11.9x to 12.0x in the cold.
Does adding 120 HP and TQ (along with the extra weight of a BBC) get me down to 10.9x? I don't think so...but I'd love to be wrong. Probably 11.1x to 11.3x, if I had to guess. I'd also be blowing out my drag radials at that point and would need real slicks.
FWIW, I've got some AFR 195 Eliminator heads on order from Straub, blueprinted and ported. We'll see happens with those this year.

 

[68Chevele]

You’re experience with the Nova is kind of how I feel about my Monte now...the engine makes enough torque to make the 2.56 feel like a small block with 3.42 gears. Street driving couldn’t hardly be more enjoyable. I’m excited to see how much different a 496 or Mark’s 511 act compare to my current 467.

The difference between a 355 and a 383 is readily apparent, but that difference is a larger percent increase than going from a 467-496. Comparing the change from a 355 to 388 to a 467-511 is more accurate. In this case, the 511 is also built by a pro...so the difference will be multiplied.

I would be willing to bet my current 461 would hit 11.90's in a car like yours as well as my 406 I ran last year, with the stock converter and 2.56's. All I have are 2.73's to test with but I suppose with the 30" tire the effective gear ratio is close to 2.56's. Would be an interesting test for sure.

 

[Dragginwagon467]

It'll feel like you just put a bigger DIESEL under the hood, that's how!

I love diesel power.

I would be willing to bet my current 461 would hit 11.90's in a car like yours as well as my 406 I ran last year, with the stock converter and 2.56's. All I have are 2.73's to test with but I suppose with the 30" tire the effective gear ratio is close to 2.56's. Would be an interesting test for sure.

If your 461 or 406 would put my boat in the 11s, I’m going to need a cage with the 511.

 

[jeff swisher]

I have been reading and following this discussion.

Very interesting to say the least.
I love the idea of it really.
Just recently my 3.70 stock 9" busted a spider gear.
100's of thousands of miles on it.
I stuck in a 2.75 gear set . I have been wanting to stick in the highway gears anyway because of fishing season and pulling my Pontoon boat 160+ miles one way (MPG) .

I did the math with your 2.56 and 26.5" tall tire and our RPM's are just almost the same with my 2.75 and 28.5" tall tire.

What an acceleration killer is what I thought after driving it a few times with the 2.75 gear.

BUT..... I raced a buddy recently who just had his transmission built in his Tahoe he has a 5.3LS with ported heads cam cold air and exhaust mods and tune.
Months ago when we raced his trans went from 1st to 3rd .. now he has 2nd under full throttle and it is much quicker ..or so he stated.

With my now highway geared car I beat him by just as much.

Odd that it does not feel as quick but putting lengths on him was just the same.

I wish I did have a big inch engine to attempt what you are attempting.
I will continue to read this thread and see what you get.

I have thought the 1500 stall I have could be swapped for my 4500 Coan..wonder how that would work out with the 2.75 gears?
I had 2.29 gears many years ago man those were fun. 95 MPH in first gear and I still beat my buddies 13.80 car.
Mine ran 12.80's at the time with a 3.70 gear..Never ran the 2.29 at the track.
Slow small block 350's.

 

[68Chevele]

I have been reading and following this discussion.

Very interesting to say the least.
I love the idea of it really.
Just recently my 3.70 stock 9" busted a spider gear.
100's of thousands of miles on it.
I stuck in a 2.75 gear set . I have been wanting to stick in the highway gears anyway because of fishing season and pulling my Pontoon boat 160+ miles one way (MPG) .

I did the math with your 2.56 and 26.5" tall tire and our RPM's are just almost the same with my 2.75 and 28.5" tall tire.

What an acceleration killer is what I thought after driving it a few times with the 2.75 gear.

BUT..... I raced a buddy recently who just had his transmission built in his Tahoe he has a 5.3LS with ported heads cam cold air and exhaust mods and tune.
Months ago when we raced his trans went from 1st to 3rd .. now he has 2nd under full throttle and it is much quicker ..or so he stated.

With my now highway geared car I beat him by just as much.

Odd that it does not feel as quick but putting lengths on him was just the same.

I wish I did have a big inch engine to attempt what you are attempting.
I will continue to read this thread and see what you get.

I have thought the 1500 stall I have could be swapped for my 4500 Coan..wonder how that would work out with the 2.75 gears?
I had 2.29 gears many years ago man those were fun. 95 MPH in first gear and I still beat my buddies 13.80 car.
Mine ran 12.80's at the time with a 3.70 gear..Never ran the 2.29 at the track.
Slow small block 350's.

I had a '68 Camaro SBC in the late 70's with 4.88's. I could just leave the car in 4th gear from a 10mph roll and beat up on all the locals. The look on their faces was priceless and it was "you never shifted", LOL.

 

[WHT/73]

I would think a 4500 converter with 2.75's would make a ton of heat. Especially if it wasn't set up for it. Now if it was....
I know 1st hand what a 4500 converter feels like. lol had/have a 10yr old treemaster. It's now in my sons malibu and can hear/feel the difference with his car having 3.42's vs my 4.30's it was made for. Still works great (he just went [email protected]) and drives it all the time but it's not optimal on the top end.
I kinda have the same issue with my 9.5/4500 converter for my 80E. It was made for the old 406 with 4.30' and now has 3.73 for the turbo's and can "feel" the difference driving without Lock up. Also temps go up to the 180's without it being in LU. Just added a tru cool 40k cooler and now it just touches 150 out of lu then drops down to low 140's hi 130's in lu.
That will decrease even further when the correct one is built for when the 441sbc goes in.

 

[jeff swisher]

@WHT/73 That is a big honkin transmission cooler.
I do have a good size transmission cooler that I got at the salvage yard for 5 bucks off of a 1 ton Van.
Flat cooling coils type.
I do not have any issues with heat in the transmission with it.
I have only ran the Coan 4500 stall with the 4.56 gears though. Less slip on the top end than the B&M 2000 stall converter.
Amazing how a good converter acts.

 

[blue_69_malibu]

Once you get a custom converter for your specific drivetrain/vehicle, you rarely ever go back to something off the shelf.
What's great about my converter is not that it helped me hit 11.99.
Rather, it's greatest attribute is that it feels almost stock/normal while driving on the street....and I live in an area with some good sized hills that I'm constantly going up and down. Pulling into and out of parking spots is totally....normal.
A good custom converter removes all of the negative attributes of driving an off-the-shelf, high stall speed converter on the street, IMHO.