Well I have a 85 305 HO TPI Iroc. Minor stuff done to get it running about 240HP and getting 27mpg down the highway around 75 right now. Trying to boost the hp and gas milage a little more. Wondering what I can expect from From doing a Air Foil? How about a throtle body bypass? Anyone running a 52mm Throttle Body, if you have one how is it? Have a 3'' flowmaster from the cat back and havent put it on what can i expect in hp and sound? How about putting a performance chip in (just picked a new one up for $20 so couldnt pass it up) any ideas on actual HP gains and if it will effect my gas milage?

Already descreened the MAF and run KN filters.

Also I havent bought a air foil or 52mm throttle body yet so if anyone has them for sale please let me know. Also looking for aftermarket runner (dont care condtiton as price means the most money is limited at this time but i have tons of parts to trade).

Thanks in advance for any help.

 

Just get the air foil, your 305 won't benefit from the larger bore throttle body. The TB coolant bypass is free and is a good mod if it doesn't get extremely cold where you live (or you only drive the car in fair weather). A good ignition module, and coil; fresh plugs and wires, make sure the injectors are fresh, and home port the plenum/runners/base, and you should see decent gains from that. You could also remove and port the heads. Keep fresh fluids in it and you should be able to add some power and keep your gas milleage.

 

Well oil is always changed around every 2800 miles. Since i bought the car at 65000miles after sitting for 5years. I right away did New plugs, Wires and MAF. Trans fuild was flushed right away with a new filter. Changed rear end fluid right away also. Also did a alternator as I run a fairly large amp for my system and didnt want my old one to go at a bad time. Car currently has 72000miles.
How do you home port the plenum and runners if you dont mind me asking as I have an extra set i could do but im not sure how to go about it.
Thanks for the help also.
Brian

 

There's a write up on porting and other valuable mods thanks to our friend at third degree. Have fun.
http://www.gmtips.com/3rd-degree/dox/tips/tips.htm