I was wondering if i port and polish the heads on my 305 if i can just bolt it back onto the block and everything will run well together or if it will lead to me having to replace other things like injectors or runners? How much horsepower does this gain?

 

Your gains are limited on a stock motor. You will see more significant gains when you add a cam.

 

could you give me some ideas for a cam that would work good with mostly stock engine, ported heads, stahl and shift kit? i have no idea on what specs i need. i want more low to mid range power, and a choppy idle, but i dont want it to sound like its choking. let me know what works good with the tuned port set up if you have any idea? do buy a set like with lifters, rockers, and everything? hook me up with some info here.

 

Give summit racing or comp cams a call and they'll help you choose a good cam!

And about the heads, port out your stockers and look for gains of around 15-20 rwhp if you do a good job and cut the valves.

If you're pulling the heads make sure to get new springs (and retainers/locks/etc.) and you might want to think about 1.6 ratio rocker-arms.

You will see a nice gain with a cam and the heads.

 

I'll agree and disagree.

Exhaust and air cleaner are more important than cam - or, put it a different way, have to come before cam.

However, I'd agree that a cam upgrade is more important than head porting. And, 1.94" intake valve installation is just about as important as porting.

What it really comes down to is porting helps maximize the other upgrades - exhaust, air cleaner, cam, and larger valves.

 

full exhaust and intake are needed to notice a big gain.

 

Yeah I agree with five7, upgrade everything else before you upgrade the heads/cam and you'll see a very nice gain.

You'll get the same gain either way, but this way your heads/cam won't be choked when they get on there!

 

Porting a cylinder head will not typically increase "low and midrange power" Porting the heads will give you a power gain at the higher RPM band above 3500-4000 rpm. and extend the usable rpm range higher.
Same with a larger cam. If you want an apprciatable result plan on improving the overall airflow in ( intake) and through (heads) and out (exhaust) of the the engine.

Generally, to take advantage of the shift in the torque band
towards the upper end you'd want to change the rear gear ratio an maybe the torque converter stall.