I have a 1985 iroc with a 1987 350 2 port tpi motor.
The motor is completely pulled apart and ready to be machined.
I'll most likely just bore it out 30 over.
My original plan was to put some vortec heads on it off a 96-98 silverado and a mild cam.

I know its a 350 and all but is 20 mpg a possibility?
Besides good tune, exhaust, and air filters. What are the best build parts for 20mpg?
Is there any way to keep power with a little economy?

Thanks in advance

 

Yea do a stock tpi build an u should see 20+ mpg make sure the torque converter lock up works if auto car if standard u could go with a lower rear end gear ratio like 2.73's 3.08's etc etc

 

second that call....my stock 305 TPI with 3.08 rear end does 26 mpg highway all day long. 20mpg city.

that said replacing the stock fuel injectors to the Bosch ones from SouthBay was a big part of that. Before I was at 19 mpg highway.......the old ones were that tired.

 

One of the goals of my build is 20+mpg.

Should not be too hard to reach ,with a light right foot.

 

yea i decided to just port the tpi heads instead. (college budget) ill do some research into the bosch fuel injectors as well. Also im converting the car to a manual with a T5.

Glad to hear that such a fun car can still get 20+ mpg.

Also that comp 500 cam, does that add mpg? or just the best cam you can really get w/o hurting mpg?

 

I can't say if the 500 cam would improve milage.

I sent Comp my specs and said I wanted good performance and milage, they suggested the 500 cam based on that.

 

I emailed them too a couple days ago. Still waiting for my response. I'm following your re re re build page to kind of guide mine.

 

I have the 501 cam with vortec heads and I would say highway doing 70mph I get about 25mpg. This is going to the track, making 5 passes and driving home after. General mixed driving, I would say I get about 20-22.

 

I have a 305 tpi with 2.73s t5 with headers and 3 inch exhaust i get 27.9 at 85mph

 

You want a 350 and 20mpg+?

Put a stock 350TPI with a T56. Done.

Do it with a LT1.

Do it with a 5.3L Gen3 swap too.

Just about any T56 or T5 equipped 350 with a mild cam and good tune will do 20mpg+ easy if its running right. Gearing is KEY.

My LT1 with a T56 got 32mpg steady state highway cruising to Road America, and on the way back with the 0% ethanol gas WI has I got 34mpg.

 

damm, that good. my 97 camaro (see sig for bolt ons) is knocking down 25mph on the hiway trip to and from work.
26mile one way. Im guess If I actually get a tune it would do a little better.
Right now its still on stock tune, so deff. not great being all a.i.r , egr is deletes along with 2 o2 because of the long tubes.

 

ok ended up getting some vortec heads ($200) and im not sure what i should really do with them... but im not going to port them. I just need to figure out what is good to do to the heads and what type of cam to get to break 300hp and still get 20+mpg. Any suggestions?

 

get a new intake manifold because your stock TPI manifold wont bolt up. scoggin dickey makes one for around 400 bucks.

 

stock 305 tpi 122k miles, shorter belt(no a/c, no a.i.r.), t5, 3.08 gears. cruising at 80mph on the highway I got 26mpg. With headers, t56, and a tune that could EASILY be 30+ mpg.

I'll let you know how much the 350 gets on the highway with the corvette tune and headers when I get time to do some highway driving. I'm going to guess 28mpg though.

 

I have a SDPC TPI intake for those heads. Its new never installed but box is long gone. PM me if intrested

 

Hope the OP see this. cause i dont know if hes done his homework on vortec heads, but if he has and already has a manifold man i would be very appreciative to be next in line

 

Your close enuff to come get it. I go to Gateway now and then, you could get it then.

 

well out of respect I'll wait till the op says yes or no, or until the next time you go out there. I'll definitely come out, honestly i have never been and i would love to bring the family!

 

I work at advanced auto parts so i can get the edelbrock vortec manifold manifold for 20% off. http://www.summitracing.com/parts/edl-3817

Is the sdpc intake better though?
I just sold my 083 tpi heads and intake manifold for $150 so theres no turning back now.

 

hell you could get more than 20% discount from just ordering online.. if you look up online discount codes you can get nearly 40% discount... i used to work there and it was funny that they offered us 20% discount and online you can get more than that... and really theres no difference between the two, they are just made to go on vortec heads, both work with big tube runners, so if ya dont have those consider getting one of the kits on ebay (someone on here may have one) for getting the dents out of your runners, supposedly they have a stage 3 kit that also widens the tubes out to the size of big tube runners, i hear good things about siamesed runners as well but i think you sacrifice torque for horsepower somewhat that way- they look neat though

 

I have the vortec heads
I will have the edelbrock vortec adapter
Also I will have a mild cam.
Can i use a t-5 transmission? or do i have to save up for a t56?
I have no clue what my pounds of torque will be...

 

Save up for a T56.

 

I was really impressed with my 217k 91 L98 car coming from Kingman AZ to West Jordan UT. (540 miles) I Filled up in Kingman and When I got to St.George I still had about a touch over a quarter of a tank, I could've easily made it to Cedar City but I decided to fill up early. When I got to West Jordan I still had a 1/4 of a tank left. I don't know how to do the math but it did awesome.

 

22.5mpg

 

Still not too terrible for such an old girl lol.

 

Not at all. I'm assuming it was stock? cut open your air filter boxes and get headers, you'll get 25 mpg easy.

 

I'm running an TPI open element, 2460's and a full 3 inch aerochamber exhaust. That's pretty much it lol.

 

yea i think thats best.
Now i have to choose a cam

 

What do you want out of your cam? CompCams has some really nice off-the-shelf cams, they're not too expensive either.

 

Yea ill shoot them an email