is the L03 worth building? i've read that you can easily achive 300 HP with a change of heads/cam/intake/tbi unit/exuast. is it worth it or should i think about just driving the L03 unit its worn out and replacing it with a 350 TBI? if you have a built 305 and a stock 350 which one will deliver better fuel millage? i want my car to be a little faster but still need to maintain practical fuel millage for daily summer driving. 300+ HP is no good to me if it spends most of its time in the driveway. i was thinking about just replacing the intake and TBI unit with a holley TBI and leaving eveything else stock. would i gain anything? im doing an exuast in the spring(hooker headers and hooker catback, high flow cat, 3" system). how much performance gain will i see just by doing the exuast?

 

Check this out....go into a thread that says "upgrades let me know" it will be in this section just a day or so ago......i posted something called lunatis 305 engine build......and i put a stock 350 next to it....just check it out....

 

dont even bother that lunati motor makes its peak at 6250rpm then what you push it to 7500 to use that horsepower? yeah i would love to see that in a street engine.... that thing is a dog... they ran it on an engine dyno so expect like 9-10% less on a chassis dyno and probably another 6-8% for heat and accesorys..and even less as your not gonna run 108 octane race gas every day so that would be almost a point of compression...so
from 343 peak HP you end up with about 268 HP that is even a little high i bet a for less money and less work and be more streetable that a 305 running a 104 lsa cam making all of its power at redline i would say go with a 350 and be done with it

 

thats exactly my point.......lunati built a 305 motor ***** to the walls........and still only took a stock 350 by a few horsepower............my whole point here is exactly what this man says......get a 350 and be done with it..........you can bore and stroke a 305 all day long and completely redo it..........but its never going to be a 350..........theres no replacement for displacement

 

oh man, I wish somebody woulda told me this 2 years ago. I've put about 1000 miles on my car since buying it, about 3 years ago. 300HP isn't that special up on blocks in my garage...

Just go at your bottlenecks, and try to only put on parts that can be re-used on a 350. So exhaust is a great upgrade now. I don't think your TBI is a bottleneck.

Notice what I bolded? Just use bolt ons you can keep for your 350. After you're done with that, get the 350, then look at perhaps going carbed or something.

 

i have no desire to own a carbed engine. the fuel millage sucks, and fuel injection is more dependable (i think). i love TBI, a very simple and dependable EFI system. i want a TBI unit that will run like a 4bl carb. i want the driveability and economy of fuel injection mixed with performance that you would expect from a good size carb.

 

Huh, ok, good luck with that. You might want to take a cue from members on here and what they're seeing good luck with. There are very few members with hot TBI motors (like, count on one hand sorta thing), yet very many fast carbed cars and many fast true FI cars. (port injection, none of this centralized injector wet intake manifold BS).

The whole "bad mileage with carb" is also BS. It's bad mileage with a big cam and 4.11 gears without overdrive. You can't run a BIG cam with FI, so they run a carb, hence "carbs give bad mileage".

Driving a fast car hard gives bad mileage, plain and simple.

I prefer carb due to the ease of modification. There are no expensive sensors to break, etc etc. Carbs are cheaper. Bla bla bla. Anyway, your call.