I have a '91 Firebird that was originally a 305 TBI. I did a 350 swap to ... an L05... Because I am a moron.

Anyways, I haven't got loads of dough to throw around, but hopefully when the semester ends and I can work a bit more I can make a few bucks. Are there any smaller sorts of things that I can do to get a bit more power out of that engine? Anything in the under $400 range? $400-600 range? What are my options?

I've a T-5 tranny and a 3.42 rear end with limited-slip, so I'm mostly satisfied with that aspect of things.

 

Why are you unhappy with the LO5 swap?? Did it not give you any significant power gains? Are you sure you used the right sensors, ECM, and injectors all for the swap?

I believe the LO5 is a non-roller motor. If that is true, summitracing sells all kind of camshafts for under $100 that would be nice. If it is a roller like the LO3, throw in an LT1 camshaft used.

Then spend some money on intake and exhaust.

 

The 305 makes 170hp. The L05 350 makes 180hp. Granted my 305 had 160,000 miles on it and the L05 was fully machined before it went in my car, there was not nearly as much gain as I'd have seen had I gone with a TPI motor, LT1, something with Vortec heads...

I'm happier with 350 ci than I was with 305 in any case, but it still leaves a bit to be desired.

 

I got an L05 too. Came in the car when I bought it. Be happy that you have a 4" bore and about 100 extra pounds of torque over stock L03

If you haven't already uncorked the exhaust with headers and full 3", do that. Then think about a cam or heads.

 

an L05 is still a good engine. main problem is the cylinder heads are restrictive. it does have the provision built into the block for a OE roller cam, or you can also use any flat tappet cam as well. so cam options are nice. the best things to do for that are a nice headers and back exhaust, a 454 TBI and if you want also change the intake manifold to either a edelbrock TBI or a holley pro-jection TBI intake. those few things will yield a nice gain. depending on what the engine is from power ratings are between 180 and 210 horse and 300 ft-lbs.

 

well the nice thing about flat tappet cams, is that they are dirt cheap, new. The only downside is you gotta drop new lifters in too, but they are pretty cheap. And you gotta run Rotella oil, or something with zinc in it to protect the cam from wiping a lobe. But I run that anyway now, because its good oil.

I am unsure, does the stock LO5 come with the Swirlport heads? If not, you could be in luck.

 

There are 3 different L05 engines, all TBI and all with swirl port heads: std passenger car (using LO3 roller cam) with 180 fwhp and 300 ftlbs, Caprice police version with 190 to 205 fwhp (depending on year, uses roller L98 TPI "773" cam), and truck LO5 with IIRC 190 to 210 fwhp (flat tappet cam, less exh restriction).

All of the above were using the factory OEM rating with factory exh and a low-noise intake. Add a decent cold-air feed and a good exhaust and you'll gain 15 to 30 hp. In a lightweight car like a 3rdgen, it's not a bad performer and it will still get decent mileage if you keep your foot out of it.

Read the TBI stickies to see what kind of power you can make. You can bump the power cheaply by doing a lot of reading here, to find out what really works and what's just hype.

 

The L05 I've got came out of a Buick Roadmaster, so it's the standard passenger car model.

 

Then the cheapest power gain for you would be to get a (used) 91-93 Caprice copcar ECM, and either a used Fcar LT1 cam or a used copcar/TPI "773" cam. The specs on these cams are close enough; the main difference is that the FCar LT1 cam has much better lift.

The ECM/cam swap would put you at 205 fwhp with the 73 cam, or 215+ using the LT1 cam, with no other changes. Exhaust and cold air mods, and a DIY FPR tweak, would build atop those (+20 to +30 hp added is reasonable). You could reach 225 to 245 fwhp (depending on the parts chosen) for very short money. Those numbers would put you even with a stock L98 Fcar, i.e. low 14s.