Ranges from an average of 10-75 horsepower and will cost from 150-2500 dollars.

Your Dart heads will support about 425hp.

 

only use good people who have been recommended word of mouth. this is not where you want to go cheap. you can do the cheap job yourself!

maybe another person from MO can recommend someone..

 

do it yourself:
buy some junk (cracked, from a Honduh, etc) heads and practice.
take your tool and do it yourself; mostly clean up the extra material and smooth out the contours. Be conservative.

Pay for it: have someone that knows his stuff do it for ya.

 

Here is a company that I have heard alot of good things about. Scroll down to see prices on porting. As far as how much hp, it depends alot on the size of your cam now,and the other engine components. If you have a fairly small cam now, and you go with a full competition port and job, and a new larger cam to take advantage of the better flow, on a street motor like yours, I dont think 50 hp would be out of the picture.

http://www.revolutionaryperformance.com/products.htm

Adam

 

how much you want to spend?

I'm with the cats that said do it yourself. head porting is a science all unto its own. that's not to say that you or i can't do it. do like said above, get a set of heads you don't care if you ruin or not, and an abrasive roll kit and go to town. all you can do is learn.

 

IMO, I dont think you'll see large gains worth the money to pay someone. Most dart's i've seen were cast pretty good and just a little cleanup was all that was needed, no major porting.

I would however recommend doing it yourself but like the other's said, practice on a junk head first. Take your time and be careful and you'll be alright.

 

$400 for a port job with no chamber work. $600 with smoothed and polished chambers and you pay the machinists bill if any other work is needed. That's the life-long buddy price. It's $1000 for everybody else

Unless you've already exhausted all other avenues and absolutely need the last horsepower you can wring out of your engine, porting really isn't worth the expense unless you do it yourself.

Larry

 

Porting properly done can be one of the most cost effective methods of improving HP. A cylinder head that flows well will make power. Why do you think the LS1/2/7 engines make 400+ HP on the dyno stock? The heads flow.
Johnsongrass has the range but to narrow it down if you want to get things flowing decent it's going to cost you around $500 to $800 for that type of head. An AFR type head I've invested up to $1500. An All Pro or Brodix raised runner/15 degree/18 degree LOTS and LOTS. $2500 is not a bad place to start.

Is it worth it, it really can be. What you want is the porter to tell you what they expect the head to flow from .200 through max lift before and after porting. You want improvement througout the lift curve. Darts can be improved. Can you do it yourself. Sure. Will it be better? I doubt it.

What we like to do is flow the head first, compare to spec type heads of similar design and say this is where we think it can get to. After porting, the head is reflowed and results shown to the customer. Again, expect to pay around $500 to 800 for that type of head.

On a set of AFR 195's (which are an OK head) we have dynoed 60+ hp increase after porting. Back to back, same motor, same dyno. Thats with about $800 into the heads. AFR's are far from optimum out of the factory.

 

I agree with rick.
Adam

 

Professional port work takes alot of know-how and time. Expect to pay a princely sum for good work. Many shops will charge at least $700.00 for a full port job with an airflow test. Once you do a full port job yourself, you will find out why it's expensive.

Brian