I am new to this site. My pride and joy is a 1984 H.O. Z28. I recently installed the GMPP 350/290hp crate engine. After I installed the new 350 I became concerned about my T5 trans and 10 bolt rear. This 350 has a lot more power than I expected, so I was going to purchase a Tremec TKO 500 series and a 12 bolt rear. Obviously this would be expensive but necessary for drag racing and our safety. My wife races also in her bone stock 64K mile 1984 LG4 Z28. If she wanted to drive my car at the track I can't have a trans or rear come apart while she is driving.

Anyway, I decoded all of my car's RPO codes on this site and there are a few that I have never heard or read about that might save me some money if this car is really equipped with these RPO's. RPO Y06(ring gear 9.50 inch saginaw S.P.O). Also RPO MK6 (man 5 spd,borg warner,2.95 1st, O/D).
As far as I know, F-body cars had either a 7.5" 10 bolt or that funky Australian 9 bolt, a crappy T5 or a 700R4.

DO I HAVE A 10 BOLT WITH A 9.50” RING GEAR?
DO I HAVE A HEAVY DUTY T5?
DO THESE EXIST?

Please reply if you've ever seen or heard of any heavy duty rears or transmissions in 3rd gen Camaros.

 

transmissions are pretty consistant, t5's stronger than 700r4 i believe, and for rears the dana 44 was the best that was offered if knowledge serves me right

 

you dont have a heavy duty t5, just the standard t5, and RPO codes were shared in difference vehicles and for different options, so the rpo you traced as being a 9.5 gear something is incorrect for the 3rd gen. you have a 7.5" 10 bolt

 

No.
No.
No.

You have the 7.5" Saginaw rear, most likely it came with 3.73 gears.

There were 2 T-5 versions behind V8s. The difference was the 5th gear ratio. You have the .73 (or thereabouts). The low-perf cars got a .63. Sounds like a good idea, but the ratios are wide enough that it always seems like it needs a 4½th gear.

No such rear exists for these cars.

Other names for "Heavy-duty T-5":

Jumbo shrimp
Military intelligence
Masculine sensitivity
Civil war
Feminine logic

You get the point no doubt.

 

he is right, and comical ^

 

You are right. I have an RPO GT4(3.73 ratio). But strangely, no RPO for a limited slip. My wife’s LG4 car does have an RPO for a limited slip and an RPO for the 3.42 ratio. You would think that a L69 car with 3.73 from the factory would have a posi from the factory. I guess that’s why they are called options.

 

Uhh...T5 is DEFINITELY weaker than a 700R4. So much weaker in fact that the factory did not build any 350/T5 cars as the trans wouldn't hold up to the torque in testing.

 

i thought it was backwards oopsy

 

Hello navy02ws6!!

There is another "school of thought" about the lack of a T-5 behind the 350, and it has to do with the CAFE standards at the time!!

As for the T-5 not being strong enough, the 1987 305 LB9 puts out 295 lb ft of torque and the T-5 trans is rated at only 295 lb ft of torque!! You wouldn't want to sell a car (1987 350 L98) that the engine puts out 330 lb ft of torque when the trans is only rated at 295 would you, probably not a good sales pitch!!

Also the T-5 trans rating can be exceeded (as far as the torque ratings go, most are a low limit, safety/warranty claims being built in) but must be done gently, there are plently of cases of T-5's behind 350's that will stand up to some good abuse!!