I have a 5.3 and a 6.2 what do I keep

dillpickle · February 11, 2024

I am currently in the process of preparing for a swap I have a 6.2(L92) with about 190k miles, it has some issues with idling and throttle response, my guess is something with the oil dealing with the VVT/AFM and probably bearings.

I am needing to remove the AFM and VVT for my swap anyway which is about $1000 alone ontop of whatever fixes I might need or maybe not if VVT and AFM are my sole issues.

I have a 5.3 with about 184k miles on it, I'm not exactly sure how well it runs atm since the radiator is destroyed.

I'm looking to hopefully achieve 500hp while being a street daily/weekend car. I'd love to get a supercharger but I cannot justify the 5 figure price tag.

realistically I don't need any more power than the 300hp from the 5.3 however its my dream car and I might as well get some more power. The 5.3 has the 4l60e where as the 6.2 will have a 6l80e which will cost around $7000, or $8000 if I want the 650hp rating

CamGTP · February 11, 2024

So what is your actual question??

What engine are you going to use?

Also a stock rebuilt 6L80e with a good torque converter will handle 500-600hp all day long with a good tune. Spending 7-8K on a built up transmission is kind of a waste. If you put in good clutches and stuff in the 6L80e, that's all it needs in a car.

dillpickle · February 12, 2024

1 hour ago, CamGTP said:

So what is your actual question??

What engine are you going to use?

Also a stock rebuilt 6L80e with a good torque converter will handle 500-600hp all day long with a good tune. Spending 7-8K on a built up transmission is kind of a waste. If you put in good clutches and stuff in the 6L80e, that's all it needs in a car.

is it even possible to get a 5.3 up to 450-500hp while being a daily driver? The 6.2 will need probably thousands in repairs who knows.

And for the transmission the base kit price is $6,350 and $7,600 for the 650hp upgrade which includes a billet TC

CamGTP · February 12, 2024

Yes a 5.3 can make that much power at the crank but it will take a rowdy camshaft and some headwork to make that power but the downside is that it wouldn't be as friendly to tune and drive. A stock 5.3 is putting down maybe 280-300hp to the rear tire, making another 100hp is going to take some work.

A 6.2 is such a better starting point. It would only take a camshaft, some long tubes and a good tune to be making roughly 500 crank horsepower.

And $6.350 for a base kit 6L80e is absurd. You could buy a brand new 6L80e from the GM dealer, toss in a billet converter and be way better off. It will hold the power no problem. There are guys making 600+ crank horsepower on factory transmission in trucks with magnuson supechargers. The trucks are way harder on transmissions than cars.

Also put it this way, a stock 6L90e behind a CTS-V that makes 650hp from the factory can hold the power. Buying a built up 6L80e that can handle 650hp per their rating for nearly $8,000 sounds kinda dumb.

Edited February 12, 2024 by CamGTP

dillpickle · February 12, 2024

40 minutes ago, CamGTP said:

Yes a 5.3 can make that much power at the crank but it will take a rowdy camshaft and some headwork to make that power but the downside is that it wouldn't be as friendly to tune and drive. A stock 5.3 is putting down maybe 280-300hp to the rear tire, making another 100hp is going to take some work.

A 6.2 is such a better starting point. It would only take a camshaft, some long tubes and a good tune to be making roughly 500 crank horsepower.

And $6.350 for a base kit 6L80e is absurd. You could buy a brand new 6L80e from the GM dealer, toss in a billet converter and be way better off. It will hold the power no problem. There are guys making 600+ crank horsepower on factory transmission in trucks with magnuson supechargers. The trucks are way harder on transmissions than cars.

Also put it this way, a stock 6L90e behind a CTS-V that makes 650hp from the factory can hold the power. Buying a built up 6L80e that can handle 650hp per their rating for nearly $8,000 sounds kinda dumb.

well I guess I'll tear apart the 6.2 once I have room after I sell my 2017 silverado for 10k. hopefully the damage isn't too bad

as for the 6l80e, that includes a standalone transmission controller, T-case Adapter, 27 spline output shaft and probably more stuff. $1250 increases the power rating to 650hp and comes standard with a multi-disc billet TC

KARNUT · February 12, 2024

I would approach it a little differently. You already have a 6.2 truck. I would do a rebuild eliminate the cylinder deactivation. I match the cam a good set of headers and tune it. Maybe add E-85 if it’s plentiful in your area. I’d gear it. Eliminating the nannies and gearing it would really hit the seat of the pants. Without hurting reliability. The nannies really affect the seat of the pants feel.