for Vang's welding comment, there is an iron "dealy" on the rear of the intake manifold right under the 4th runner, held on by 3 12mm bolts. You'll need to either weld that hole (aluminum) on the manifold, or weld the hole on that iron piece and bolt it back on. If you're MacGuyer, you can just JBWeld it.
You'll also be left with a hole on the exhaust manifold, which doesn't require welding. For this you can do the $0.05 trick. On the exhaust side, there is a ~3/4" pipe with a nut/thread on it. Hack the pipe off just after the nut. Unbolt nut, insert a nickel into bung, retighten the nut. Done.
The rest of it is just capping off vacuum hoses. If you're eliminating the charcoal canister, then you'll be left with a single vacuum hose to the FPR from the back of the intake manifold. If it's an S13, there may be some secondary butterfly garbage, too. Don't know, never seen it.
Removing emmisions parts results in a gain of 0hp, by the way.