i have an older 350 truck motor in my t/a with 441 heads adn i also have an lg4 305 just layin around, im wondering what i would gain if i sent the 305 heads to a machine shop and had them ported and maybe bigger valves installed? what else should i do to them? what will it cost? adn what kind of gains will i get? thanks alot

 

Really depends on how much heart the shop puts into the port job. But I get good results out of these heads.
Some shops don't have experience on these heads and may turn there nose up on them with a preconceived notion that they won't flow or perform.
If so:
Do the porting yourself. Its not hard, just time consuming. (you'll need a electric die grinder, some carbide cutters {3} and some stones and emery rolls.)
Use new 1.94x 1.60 valves on a 350 motor. Don't be shy on the porting, Pin the studs yourself to save money.
The stock exhaust spring seats are machined deeper in these heads. (will need .105" of shims to equalize the springs height with stock retainers.)
Pay the shop to do what they do best. The valve job and guide
spring seat machining etc.

I get 234 to 240cfm intake and 180+ cfm exhaust.
There will be a dramatic difference in power compared to your stock 441's.
With the new ported 305 heads and higher compression the motor will respond to a bigger cam too.

Search my past posts for more info.
Search Sitting Bull's posts for good pics too.

 

that sounds great, i might just pick up some old junk heads at a junk yard for a couple bucks to practice on, how do i know how much to shave off the heads? i think summit has a kit that you can use with a dremil tool. i will deffinately do some searching and try to find out all i can but if u dont mind me asking, how much money did it cost you to do your heads? as of the moment im on a really tight budget wich is why im not going out and buying aftermarket heads. i figured ill do the heads this summer, then next winter ill have a cam put in. also what kind of setup are you running? can u compare before and after? thanks

 

Yes Summit sells some of the tools you'll need but a dremel won't cut it.
Sears sells a good Electric die grinder for around $100 US.
thats the one I use.

Check out Competition Products for tons of stuff for the budget racer/engine builder. Its near you and they ship to your door.

Can't really tell you what it costs cause I get some good deals from friends on machining. But you should shop around and find a shop that suites your budget in your area.
But you should be able to do it for right around $400 all said and done.

The more work you do yourself, the more you'll save.
My set up is a bit on the radical side. Actually I'm just finishing up
installing my ported 305 heads , intake and and larger by huger solid cam. I shaved the hell out of 'em (52cc's) so the compression is going to be 12.6:1 (race gas)
You can measure your actual cr once you remove your stock heads and shave/setup your 305 heads accordingly to get the cr you want on your motor. ( THEY'LL BE ABOUT 60CC'S WITH THE BIGGER VALVES) Use a cam with .450 to .490 lift and 214 to 224 deg @.050 duration for mild/ moderate street motor.
I replaced a set of vortecs with these heads.

Track testing is coming soon. Ran 13.0's @104mph with the vortecs and a mild cam.

Expecting mid 12's @about 106/107 with this setup.

You should be able to sell your old 441's for decent $$$.
Some Dirt Track classes have to use these heads.

 

so, it will cost, like 100 for the kit, 100 for the grinder, 100-200 for machining? but at a shop they charge like 300-600 to do it all and they do it about half a$$ed? after searching adn looking at sitting bulls post with the pictures im wondering what all has to be ported? and is there a kit i can buy with the valves and springs and stuff? and how much will the valves and springs cost? i really dont know much about heads other than how they work. im lookin on the web for a kit that has like full instructions and all the tools needed to do it but so far i havent found any. i will have a full bottum end of a 305 and 441 heads to sell afterwards but iv been tryin to sell the 305 forever but nobody wants it. what all does the machine shop have to do? im going to start calling around trying to find out some prices. thanks for all your help!

 

Yes there are many shops that will try to soak ya and do half *** work. Many good machinists know nothing about porting heads either. (so do it your self) Find a good one, Know what you want done and discuss it with them before hand. Get an estimate.

You can go through the Competition Products Catalog and price out all the hard parts you'll need.
There is no All in one Kit you can buy.
But if you look in the catalog there are packages you can buy.

You can buy a good book on doing budget performance buildups
on small block chevys that will be well worth the $10 spent.
Head preperation and much more is covered in it.

Look Here

Read it, Know It.... There will be a test...

 

wow, u have it all covered dont ya im gunna do some searching and find out all the info i need and ill call around to a few places see what i can get done. thanks alot for all your help!

 

forgot to ask one more question, how do i know how much to take off? and where? and will my 416 heads work ok? in sitting bull's post it sais to avoid tbi heads but i think my lg4 was a tbi when it came from factory? thanks

 

Its all in the book and the 416's or 081's are the ones to use.
You have the right heads.

Get an old cylinder head and grind right through the port wall.

Grind a little less on yours......Hha Hha ha ...
Just kidding
You don't need to make the ports huge for your purposes.
No need to grind through.

 

ok, how much do i take out under the valves? and around in those areas? do i actually make it bigger or just smooth it out? thanks

 

Both,, buy the book...

 

on the performance side, what will i gain if i just port the heads, put on edelbrock performer intake manifold, my performer 600 cfm carb, and flowtech headers that go into stock pipeing? then hopefully in the winter i will get a 3 inch cat-back and a cam. but for right now what kind of performance boost will i see? i read in sitting bulls post that i should expect a 10 - 15% increase in hp and thats only around 30 hp and iv heard u dont REALLY feel it unless u get around 50 hp gain. also what if i kept the stock valves in there instead of replacing them with the bigger ones? i could save on machining and i don think the valves on my 305 are very old.

 

The stock 305 valves will not work and will not save you money.
A valve job is a valve job... Cost is the same.
new bigger valves are cheap ...
remember, the stock 305 heads valves are smaller than the valves in the heads you'll be replacing.
The stock exhaust system or any part of it will really hold you back.

You can realisticly expect to get out of it exactly what you put into it. All depends on how far you want to go.
30hp would be a minimum.

 

i found a set of bare 772 vette heads that have 58cc chambers and they are already ported and polished. if i can get them for cheap enough and i take them in and get a valve job and all the good stuff how well would these work? better than the 305's? thanks

 

3748772 is a a old 283 head. could be good with larger valves
and good porting but they don;t have accessory bolt holes.

 

Listen to F-Bird. I just did my 081 heads up. The grinder was $50.00 at sears. I bought 2 carbides from www.carbideburs.com for $15.00 each. They were 6 inch long burs. My machinist just called and told me $150.00 to grind the valves, open intake up to 1.94, grind both the intake and exhaust seats and valves, set the valve spring heigth, install new seals, and finish off the bowls to match the 1.94 valves. I only ground the intake bowls to the ede of the 1.84 valves. So for $230.00 plus your time, you can have some kick *** heads. I will be getting mine back Friday, and if you want pictures I will send them. Also, you can do you own machining. I bought a stud boss cutter years ago and I used this on my heads to cut the stud bosses down. Once cut down use a chisel and knock off the extra material. Then get the Proform stud tapper tool and tap your own threads for screw in studs and guide plates. I told my machinist that I did it my self and he could not believe it. Proform stud tool is $16.00 at Summit. The Boss cutter varies. Try PAW.

 

yeah, it would be great to see soem pictures! it only costed u 230? thats cheaper than i can get those heads and get a valve job done on them. let me know how much better your engine does too!

 

could you explain a little more, i know nothing about heads!