Hello gents. Guy on another forum has this higher stall converter for sale.

JEGS Performance Products 60406, JEGS Torque Converters | JEGS Performance Products

He had it behind a windsor. Just wondering if it will bolt up to the flexplate in my '77 with a 400? I have a C6 which I believe is not the original to the truck. The dimensions of the flexplate it bolts to are listed but I don't know what the dimensions of the stock 400 flexplate are and my truck is currently together.

I put a 2400 RPM stall in my mostly stock Lightning years ago and man, what a difference it made...

 

Not sure on the fit but an observation. The lightning engine is an RPM engine. The high stall converter lets it slip up to higher RPM and makes it snappier.

The 400 is more of a torque engine. The high stall converter may not help much plus more heat in the transmission and worse mileage. Not sure you would be happy with it.

 

Actually the stock Lightning 351 makes a good bit of low end torque (not as much as the 450 ft.-lb. my 408 does). A 2400 stall is pretty mild for a street rig. Drag cars use anywhere from 5k-8k stall converters. I guess after having a built 400 with an NP435 behind it I'm not real happy with how this one moves out with the automatic. Eventual plan is for a T-56 so I can row the gears

 

Anybody? Bueller?

 

From what I am finding, it looks like 351W and 400M both use the 11.4 inch bolt pattern.


However, I would agree with Blue and White's point. Your torque peak on the 400M is only 2000 RPM in stock form. The converter you linked has a stall speed of 2400-2600 (400-600 RPM past the peak and well on the downhill side of the torque curve). This TC may be mild for many street applications, but not necessarily a truck. As long as your motor is built for higher RPM racing use, you may be good. If not, it will perform poorly under load and add unnecessary heat.

 

FE's use the odd ball pilot, and all the c6's I have seen...300 302 351w m 400m 429 460 (and owned) all use the pilot and pattern your looking at with Jegs.

 

If you go for it, be sure you have between an 1/8" minimum and 3/16" maximum clearance between flex plate and converter on the converter pads before you tighten converter nuts.