I'm trying to plan a build-up of my 350. Right now it's a L05 roller with 193 swirl port heads and who knows what cam.

I'm going to be running TBI and I have a larger TBI unit available if I need it. My goal is to run 12.99 and keep my average city/highway MPG in the high teens. Is this possible? If so is this possible on 87 octane? This also must pass the sniffer and visual test as a 305, so heads must be iron and intake manifold must look close to stock. I can tune my TBI setup. The car is already completely built up around the motor with supporting mods so all that's left is the motor.

Driveability as well as low and midrange torque is important to me. The car is to be daily driven around town and I'd like to keep my peak power below 5500 RPM so I dont have to rev the car like crazy to use my power. The engine has to cruise well and efficient between 1500 and 2200 RPM.

I hear vortec heads are good for this type of deal but require a special intake manifold. Will I find a stock-looking intake manifold for vortec heads and TBI?

I also have read that stock L98 heads are good too. Thoughts on these over vortecs?

Cam is the most important thing so I was thinking after I plan the rest of my buildup I would talk to the cam companies.

One last question...with all my driveability and RPM requirements would upgrading the short block to a 383 be a better choice for me?

 

Sounds like the easiest way to get everything you want. Loads of torque, it'll tame a bigger cam down. With good tuning, passing the emmisions shouldn't be hard. Mileage in the high teens should be easy with good tuning, and a decent rear end ratio, and of course maintaining lockup if your auto.

 

GMPP p/n 12496821. $349.95 from Summit.

 

with a mild 350 I may recommend a comp xe256 or 262 cam for your set up and planned goals. Im currently running a 256 in a mild 350 with intake headers tuning etc. It will push my 4300lbs truck to low 15's in the 1/4. So I dont have a calculator for the difference in weight but that should be close to getting you into the 13 to 12 s range in a lighter car. It mild enough for good mileage,doesnt need much converter or gears and I average about 19mpg all around and 20plus on the freeway. Not great but not bad for a Pu. Thats with 3.08 gears and a 700r4. Just my thoughts.

 

I've got my Vortec/xe262 setup going in soon. I'll let you know how it works out. I've got the GMPP Carb intake for it, I bet it's the same as that TBI intake aside from the mounting flange and the price...

 

IMO Vortecs would be your best option for keeping iron heads with peak hp around 5500. The L98 heads are good, but they don't swirl/flow quite like the Vortecs. I'd actually say that your next best option after Vortecs would be ported L05 heads. (it would be a good money saver too if you port them yourself)
Double roller rockers, a Lunati Voodoo 60120 or Comp XE cam that gives you peak torque around 3000rpm and a powerband to 5500. A good intake to match and you're good to go. (assuming your air intake and exhaust are up to snuff)
I don't know if this will pull 12's but it would be quick.
With the 700R4 you should have a cruise rpm around 2200, which would be right near the sweet spot for the highway with a 3000rpm peak torque.
You could easily get well into the 20's mpg wise with some good tuning (look at fast355 with his giant van getting 18 mpg)

 

Say I go with the vortecs and the appropriate cam company's recommendation and GMPP Vortec TBI intake manifold as you guys have recomended. Would I do anything special to the top end setup if I said I wanted to swap a 383 short block under everything down the road for the final push to 12s?

 

That intake and vortec heads are not smog legal in CA. you run the risk of wasting your time and money hoping that you will not be noticed. A vortec engine is not acceptable for an engine swap because it never came in a passenger car. As much as I hate the smog laws of this state, if i were in the smog tech business, that intake would jump out at me and I would not be willing to risk my livelihood so you could pass. My assumption would be that you are a state agent trying to test me. Once you are hooked up to the computer, you'd be failed for tampering with the induction system. The glass is always half empty in my world.

 

If you're totally rebuilding the motor anyway, might as well go 383.
If the shortblock is in good shape, 350 cubes is more than enough to get you to the high 12's with Vortec heads and the mild cams that were mentioned above. If you do a decent build with those parts and get a good tune, and you don't get into the 12's, it's not gonna be due to the motor; it will be due to traction, gearing, and stall.
12.9x ET's and only high teens for mileage is not an aggressive goal at all.
Any decent 350 build, a 3000 stall converter, 3.73 gears, and drag radials will get you there with a 3rd Gen.

 

Don't I haven't stopped thinking about that very issue. I printed out a picture of that manifold and took it out to my car and even if I painted it black it is very different.

Is there such a thing as an aftermarket TBI intake manifold that is 50 state legal? Or at the very least, is there such thing as one that is pretty much identical to the stock one if painted black?