Super Stock GT class question

[Gene Daugherty]

Is it legal to run a powerglide transmission behind an LS engine in Super Stock GT classes?

[FireSale]

GT is based on SS unless otherwise noted. SS Trans reads Any automatic transmission same make as engine. Max of three forward gears unless the car came with more or less.

[Gene Daugherty]

Thanks Dale

[Mark Yacavone]

Originally Posted by FireSale

GT is based on SS unless otherwise noted. SS Trans reads Any automatic transmission same make as engine. Max of three forward gears unless the car came with more or less.

I don't know if that's a direct quote but the trans has to match the engine, not necessarily the car, in GT.

[FireSale]

Originally Posted by Mark Yacavone

I don't know if that's a direct quote but the trans has to match the engine, not necessarily the car, in GT.

2019 NHRA Rules
Super Stock
Section 12A
Page 5
Page 154 overall


TRANSMISSION, AUTOMATIC
"Any model transmission, same make as car, with a maximum of three forward speeds (unless OEM equipped with more than three forward speeds). O.D. gear not required, reverse permitted. Transmission case must be OEM or aftermarket OEM replica from a standard automotive application as found in the Official NHRA Stock Car Classification Guide...."

No special notes for trans in the GT section, so these rules apply.

"Make" means "Manufacturer" (Ford, GM) and "Model" means part ID (Glide, ect for GM, C4-C6 for Ford ect). Correct me if I have this wrong.

[nhramnl]

Originally Posted by Mark Yacavone

I don't know if that's a direct quote but the trans has to match the engine, not necessarily the car, in GT.

This might be what you're saying, Mark, but I read the rule to say that ANY model transmission that is the same MAKE as the car, so long as it has no more than 3 forward speeds (unless it came with more, blah, blah, blah) is allowable. My interpretation is that as long as it is a transmission that was installed in a General Motors production vehicle, it is OK. If that is in fact what it says, a Powerglide would be "legal" behind any GM engine, in a legal SS/GT car. It does NOT suggest that a Powerglide would not be legal behind an LS engine, because they were never built with Powerglides.

[Mark Yacavone]

Originally Posted by nhramnl

This might be what you're saying, Mark, but I read the rule to say that ANY model transmission that is the same MAKE as the car, so long as it has no more than 3 forward speeds (unless it came with more, blah, blah, blah) is allowable. My interpretation is that as long as it is a transmission that was installed in a General Motors production vehicle, it is OK. If that is in fact what it says, a Powerglide would be "legal" behind any GM engine, in a legal SS/GT car. It does NOT suggest that a Powerglide would not be legal behind an LS engine, because they were never built with Powerglides.

I think that's what it means too. Good question though. I had wondered about retrofitting a PG .

What I was getting at was that first of all, an automatic has to be available with the engine used. ( i.e. no 302 Z28s with automatic).
After that hurdle , it seems to be wide open except for this. An injected 305 from an 80's Camaro, in a 66 Chevy II, could use a 2, 3, or 4 speed automatic, whereas a 350/255 combo in same car would be limited to a 2 or 3 speed. The PG would be grandfathered in, in this example.

Nobody uses a 200 4R in class racing that I know of, yet. I say yet, because there's only so many 200 3 speeds left, unless we want to start digging them up out of landfills, or maybe get China to send some back, before they're turned into H.F. tools.

[Dan Fahey]

Originally Posted by FireSale

2019 NHRA Rules
Super Stock
Section 12A
Page 5
Page 154 overall


TRANSMISSION, AUTOMATIC
"Any model transmission, same make as car, with a maximum of three forward speeds (unless OEM equipped with more than three forward speeds). O.D. gear not required, reverse permitted. Transmission case must be OEM or aftermarket OEM replica from a standard automotive application as found in the Official NHRA Stock Car Classification Guide...."

No special notes for trans in the GT section, so these rules apply.

"Make" means "Manufacturer" (Ford, GM) and "Model" means part ID (Glide, ect for GM, C4-C6 for Ford ect). Correct me if I have this wrong.

Does anyone use the OD feature on the 3 speed plus Overdrive transmissions?

D