ParKer85z

looking to hop up stock 305...not sure whats the best heads to go with..any suggestions..also intake...its carbureated..have headers and exhaust figured out but open to suggestions...thanks

lookin to get the most out of the motor already in it lol

Ozz1967

iTrader: (4)

It all depends on how far you are willing to tear down the engine.

Easiest mods are headers, 3" catback with a good high flow muffler and high-flow cat( if you are keeping emissions). If you aren't keeping emissions, you can get headers that don't have the A.I.R. provision and get rid of your cat and smog pump.

From headers and exhaust, I'd go with an Edelbrock Performer Intake because I don't believe the Air Gap or RPM intakes will fit as they sit too high and your air cleaner will hit your hood.

For heads...probably the best heads you will find for the 305 are the World Torquer SR heads for a 305. You can find them on their web site, also you can find them on Summit Racing's website here:World S/R Torquer 58cc heads

Another option is to take your heads, port and polish them and install 1.94 intake valves. MWNOVA66 on this site has done that to his heads and he's been really happy with the results.


Beyond this you get into swaping out the cam, boring and stroking the block etc which means you get to take the motor out of the car but I think that's more than you are intending to do by your post. Hope this helps!

aciddrop2804

I would recommend these trick flow heads http://www.summitracing.com/parts/TFS-30300001/

combine them with some roller rockers, a cam, exhaust, and a new intake manifold and you will see a pig jump in hp.

chevy high performance magazine used this combo with great results. gained 53 HP and 55ft/lbs
heres the article:
http://www.chevyhiperformance.com/te...aro/index.html

ParKer85z

thanks man that helps alot. yea rebiuld is in the future but i want to get a lil more performance if im goin to start fresh and i think your suggestions will be right up my alley.

aciddrop2804

actually after looking at both sets i think either one would suit you just fine. the ones i picked were just a bit cheaper and 56 cc. you just need to make sure the cam you pick works well with the heads. after CHP tuned the carb, they were able to get another 15-20 hp and tq so that actually a fairly cheap yet big increase build. It went from around 145 hp wheel dynoed to 210 which means probably like 250-260 hp at the fly. not all the bad for a little ol 305!

also keep in mind they were trying to stay "california legal" so the smog pump stayed on and everything like that. the removal of that stuff should also net you a few more hp

five7kid

iTrader: (14)

The removal of the A.I.R. system will net you nothing more than the weight reduction from removing the parts. The pump doesn't use enough power to even show up on a dyno.

Air Gap intakes are not higher than non-Air Gap intakes. The gap is produced by dropping the floor into the lifter valley, not by raising the carb mount. RPM intakes will fit with a drop base air cleaner.

There is a thread on the FAQ forum about the differences between 305 engines and performance upgrades. It is all well covered in there.

aciddrop2804

just thought of something else haha, get an underdrive pully kit. they are around 100 bucks and add about 8-14 hp. not that much but hey, its not expensive either. they come with or without an alternator pully. if you use that you might have to get a bigger alternator. if you do not use it you should be fine