Ok.. so I am over hauling the engine, as seen in the other thread made by me. I dont have ANY idea waht to do w/ the heads.
1.) Keep orignal cast iron's, and just put in new springs, lifters, rods, etc..
2.) Buy aluminum L98's.
3.) Buy some other brand of heads that are very nice, and don't cost much more than $400.

Any suggestions?

BTW.. I am camming the car too, so keep that in mind
Thanx all,
Matt

 

The stock 305 heads are suffice and are actually pretty good heads. The heads were never the problem with the 305. Alot of people run 305 heads on the overrated 350. Just have them magnafluxed, and if they check out fine, have them machined and just get a new set of springs, retainers, seals, and rocker arms. Check out Crane Cams, or Competition Cams. I see them offering package deals that have springs and retainers in a kit if im not mistaking. You can also get good Cam deals that include the Camshaft, and the lifters. All that basically leaves is for you to get a set of pushrods, if you desire.

Good luck Matt.

 

if u use a stock 350 (L98) style head your going to lose compression and itll run like ***.

u can either find some good aftermarket 305 heads,but im not sure if ull find something for $400.

if i was u and u want to keep the 305,u could get them ported and polished,maybe stick some bigger valves in them...depending on cam size.

 

Hmm.. I always thought that the stock heads sucked ****. BUT.. since you claim they are acutally rather nice, I think I will just get new springs, retainers, rockers, and rods. Hm.. now I am rather.. relieved that I am not going to have to fock w/ getting new heads

 

No such thing as a very nice head that costs less than $400. I dropped that much and more in the springs, retainers, valves, etc, etc

 

Pay attention....he said aluminum L98's (only found on the 'vettes - 58cc chamber, just like the stock 305 head).

If you are planning on pulling the motor for a rebuild, and camming it, then you should def. get a set a better set of heads than your stock 305 heads. Even a set of 87-92 305 heads would be an improvement over yours (these would be on '87 LG4's and all LO3's).

- Justin

 

Hm.. I will call around local junkyards and find out if they have any LO3 or LG4 heads. But if they ask too much, I am thinking just get hi-perf. Comp Cams stuff, and be done with it.

 

A more power oriented valve job and pocket porting is the best way to get power out of stock heads. A complete cam kit with stock sized springs will keep the headaches down.

Going to an iron L31 Vortec head and a serious camshaft to match can probably get you more power but a lot more machine work would be best and that'll cost more money. Not to mention the new intake manifold you would need to buy($200).

An aftermarket head like the World Products 305 S/R doesn't look good to me at all. A cleaned up stocker would be my plan. Goodluck!

More compression is never a bad idea once a larger camshaft is going in also. A thin head gasket is easy. Milling the head is up the the builder I guess.

 

What is pocket porting? Why does the World Products s/r not look good to you? Is Millin the head really worth it? Is there anything noticeable about it power wise?

 

Justin, Why do you think the 1985 heads are any worse than the 1987-1992 heads? The 1985 heads have less shrouding around the intake valve, and they do NOT have any swirl-port technology to get in the way of air flow. I am of the opinion that the 1985 heads offer a lot of porting potential. I do have some 1986 heads on my 101 MPH capable 305, but the pre-1986 perimeter valve cover bolt design appear to offer better potential air flow, especially when drilled for a 1.94 intake valve.

Oh, and another little-known fact is that pre-1986 LG4 and L69 heads are IDENTICAL heads. There is no "305 H.O."cylinder head. The difference in the two shortblocks was the piston & cam.

Oh, and pocket porting means the area directly underneath the valves. The throat, down about 0.750 inches from the valve seat, and the valve guide boss.
Here's some pocket porting pictures I took of my own 305 cylinder heads:

Stock chamber and ports: http://www.ws6transam.org/car/chamber_nonpolish.jpg

Pocket ported exhaust and intake:
http://www.ws6transam.org/car/cylinderhead06.jpg

Polished combustion chamber with 1.94 intake valve installed:
http://www.ws6transam.org/car/chambershot.jpg

For your reference, I took these pictures from my web page on porting 305 cylinder heads:
http://www.ws6transam.org/ported.html

 

Does pocket porting actually provide noticable benefits? Thanx for the link bud!

 

Absolutely. The area directly behind the valve is far from good. Rough from the casting process and I'm no expert but there may be a ridge from the valve seat that can be taken down. Dan's website pics show the execution perfectly and he learned how to do that by reading a few books, right Dan? A few physics and dynamics classes never hurt either but that's besides the point!

 

I've read a couple of books, 'tis true. A good place to start is the Standard Abrasives website. There's also a good book by Dave Vizard on performance porting cylinder heads, but last I checked it's out of print and hard to find.
Sorry, can't help you on the physics & dynamics classes, but they are available at MSU, U of M, Delta College in Bay City, and probably most community colleges. Another good place to look is at the bookstore at www.sae.org where there are plenty of really cool automotive related books. I've been a member of the Society of Automotive Engineers since 1994.

 

Hmm...I guess I was looking at them from more of a stock pov, I admitedly don't know a lot about head design, etc. I make some recommendations based on what I've read/heard from people I trust. The machine shop that did the work on my heads made sure I had the centerbolt heads on my 305. (the project in my sig started over a year ago as an LG4 with a blown headgasket that I picked up for only $250) They said that they have more potential. I haven't really taken a close look at the two side by side.

Thanks for the info....

- Justin

 

We pocket ported a set of 86 305 TPI heads,gasket matched, added 1.94 intake valves with a 3 angle valvejob, backcut the valves, and removed all casting flash throughout the port. We stuck these heads on a stock 90 350 TBI shortblock stuck the 86 TPI equipment back on and put it in an 86 T/A. The car ran consistant low 14s (no cats, homemade cold air, cat-back, 2500 stall, 3.42 rear) at 97 to 99 mph. We later added some ported 193s with basicly the same work, removed swirl vanes. and gained a few hundreds of a sec. (well within correction factor)