Drive train help
 

Hi, I am in the process of building a gen 6 454 from my old work truck. That truck had a turbo 400 and a GM 14 bolt rear with 4.10 gears. My new frame came with an Eaton HO52 and I'm not sure what gears are in it but from everything I've read the most common gear size was 4.57. My question is, with the 4.10 gears and turbo 400 my old truck would cruise 70 mph at 2,300-2,500 rpm. If I get a set of 4.10 gears for the HO52 and put the same big block in the truck after building it (yes I know it will never cruise that low again after taking the rear wheel HP from 290 to 500) what would be a good 4 speed or 5 speed transmission to use for good take offs good quarter mile times (not looking for 10's just a respectable number for a pickup) and good streetability. M22, NV4500, etc etc etc. I'm still new to figuring out transmissions as I've not learned as much about them as I have about engines. Any help would be greatly appreciated. I don't want to buy the wrong transmission for the truck only to find it out once it's on the road.

Thanks,
Stephen

Re: Drive train help
 

You’re basing all your considerations on incorrect info.
The only way you could cruise at 2300-2500 rpm with 4.10’s is if you have 40 inch tall tires.
A 500hp motor is pretty stout. Likely won’t be happy cruising under 2800 rpm.
You need to figure out what gears you have and then figure out your trans.
And how’s the budget? Could be up to 4 grand for the right trans.

Re: Drive train help
 

With the overdrive in the truck that's what it was doing on 32 inch tires. I said I know it won't be that low again and was asking about the right transmission. I checked this morning and ifi read correctly then I have an HO72 not a 52 and it already has 4.10 gears in it. Sounds like a broken shaft inside though so I'm going to have to search for a new one. Don't really want to switch everything to 14 bolt stuff if I don't have to. I will also be searching for a locker for it. But back to the main question. I'm trying to figure out what a good 4 or 5 speed transmission would be for an engine with that amount of HP. And yes 500 HP is stout but it's just scratching the surface of what that engine is capable of. Again any help would be much appreciated.

Re: Drive train help
 

Update, the shafts are fine. So an additional question would be when I spin one tire shouldn't the other spin the opposite way if it's a limited slip?

Re: Drive train help
 

Open differentials....trans in park, both rear wheels off ground, spin one tire clockwise, other tire will spin counter clockwise....

Limited slip differential...trans in park, both rear wheels off ground, spin one tire clockwise, the other tire will spin in the same direction...

Both of above assume an axle is not broken...

:chevy::chevy::chevy:

Re: Drive train help
 

dead on


4l80e would solve the rpm at cruise issue

Re: Drive train help
 

Are you saying you have a Turbo 400 with a gear vendors overdrive attached?