fasteddy

On these engines, is external architecture the same for trans (6l80 or 8l90), and engine mounts and accessory mounts?

I want to swap the L83 from a Tahoe and replace it with either and LT1 or an LT4 long block.

There is very little info out there on the cross compatibility of these engines and even less experience.

But I'll share something I found out.....the L83 and LT1 heads accept the same whipple supercharger assembly. The valve sizes are different though.
According to Whipple the intake opening is the same size.

Although the LT4 has a different head, for boost!, I wonder if the same whipple will fit on top of the LT4 engine.

Because if the external arch is the same and the whipple will fit, I would prefer to use an LT4 long block, which is forged and designed for boost.

The LT1 crate and LT4 long block are comparably priced around $8500 and both come with warranties.......

Anybody know anything else? Can I swap an LT4 long block for the L83?

Bob@BruteSpeed

iTrader: (16)

LT1 and LT4 have an 8-bolt crankshaft pattern, which is the same pattern as the LSA. The clutch/flywheel kits for the LSA fit the LT1 and LT4.

The LT4 is based on the same Gen V Small-Block architecture as the LT1 engine, so the motor mounts for the L83 should work.

You would have to use the LT4 front accessories due to the blower being belt driven. Bob

fasteddy

I have a Whipple atop my L83 now....
What I want to do is slide a 6.2 underneath the Whipple.

Optimally I'd like to use an Lt4 long block because of the forged pistons, the special heads, and the warranty.

BUT....the LT4 heads do NOT have the same intake bolt pattern for the charger as the LT1/L83. Boo-Hoo. I can have the heads machined for the bolts but.....not sure its worth it.

Now my options are
1. LT1 Crate but not forged and some inherent weakness in the main bearing studs/fasteners.
2. Forged LT1 long block from Texas Speed.

Most likely will go with the Texas Speed Motor for now.

Bob@BruteSpeed

iTrader: (16)

http://shop.brutespeed.com/Engines-S...ocks_c3463.htm
Have you looked at what ERL offers? Check out the ERL block and shortblock packages at the above link. Bob

fasteddy

Yeah....Those look pretty badass.
Expensive too!

I need to get the motor as complete as possible because the mechanics here in socal need simple.....bolt out, bolt in works best. The last recession wiped out 98% of the aftermarket shops.

I'm concerned enough about doing a long block because they have to install the fuel injection.

With the short block (and 427 would be badass) they would have to install cam, cam phaser, heads, and fuel injection.....just too much could go wrong in that process......Too early in the LTX aftermarket lifecycle I guess.

To do that I would need an engine builder and a place that could run it on an engine dyno to ensure quality and completeness.

Bob@BruteSpeed

iTrader: (16)

That makes sense, it has to be rough over there trying to build a car. I give you a lot of credit! Bob

fasteddy

I will get there.....just a little more research on the fuel system.

Then will come the tuning.

But in the end it will all be fine and I'll have a Tahoe with a forged 6.2 (maybe even a 416) with a whipple on top and a CARB EO sticker for the smog police.

Whipple is planning to come out with a LT4 charger. Maybe the base might connect to the charger I have. Then I would have options.

Bob@BruteSpeed

iTrader: (16)

Sounds like a good plan! Bob