Is it possible to upgrade a LS1 with factory parts to get 100+ horsepower ? Or would it be easier to use aftermarket parts? I thank you in advance.

 

Might be best to just drop a blower kit in.
This was just asked in a current thread.
100HP; I'd go cam, used 243 heads, headers, depending on your year a newer intake manifold...

 

If you're talking about stuff from GM performance parts, I could be mistaken but I don't think they have a hundred horsepower on the Shelf. Not in replacement parts for an LS1 anyway.

 

In my build I used a combination of GM and aftermarket parts. For example, I used the LS2 timing chain and the LS7 lifters. And pretty much everywhere I used GM gaskets. For my heads, I got a set of CNC ported 243/799 heads for PRC... so GM heads but ported. For my camshaft, I went aftermarket... Cam Motion Titan 4 for me, but they have other options too depending on your goals. My oil pump I used a Melling 10295, but a GM pump is ok too. Headers and exhaust will typically be aftermarket, tho the z06 titanium exh is popular (light weight, quieter). As mentioned, the LS6 intake is a good upgrade vs the LS1 intake. (starting in 2001, all LS1's got the LS6 intake manifold).

Most of these threads follow the same progression. OP asks how to add XX horsepower. All the responses ask what are your goals. There are numerous ways to add horsepower and just achieving a specific power number may not actually make you happy. Is it a DD? Drag car? HPDE? What year? How many miles?

And keep in mind, if you still have the stock clutch, and you add 100hp, you're going to need a new clutch. If you have an automatic and add a big cam, you'll likely need a different TC with a higher stall. It's a slippery slope.

 

What is your end goal rwhp and is this a manual or auto?

 

How fat is your wallet? Adding 100rwhp doesn't come cheap.