[cougarmanjr]

Fellow Cougarheads,

Wondering if anyone is running Aussie heads on their 351C? I planning on rebuilding my 70 2v motor and want to get more power. I was thinking that putting on a set of the Aussie heads with their higher compression would help.

Anyone have any experiences with them?
Can these be run on pump gas?
What is the best source to get a set?

Thanks for your input.

 

[Ray]

OZ

This is an excellant upgrade You will not be dissapointed.We used the Ozzie heads when we raced Cougars in the early 90s.We were always in contention with the two Dodges and the fastest chev.We were the only Ford running and finished first in points.Grab em quick before someone else does Catz ya

 

[modifiedmark]

Aussi heads were ok years ago when nothing better was available but now thankfully we have several options that are much better. First off the cleavland heads are heavy, they require a special (read expensive) intake manifold that is only made my B. A. Ford products, they take up alot of engine bay room, the extreamly large ports dont make much torque at lower rpms and you can run into piston to valve clearance problems with windsor pistons. Also headers for a cleavland may not fit the chassis quite the same with the different deck heights. Depending how much power you want to make ( = how much money you want to spend) there are better flowing heads from World products, Air Flow Reserch, Twisted Wedge, Eldebrock and of course Ford SVO. Most are available in aluminum and the World products (Dart) are in good old cast iron. I personally have had experience with the darts and can only sing praises to them. They have good power out of the box with all the room for porting you could ask for and the thick cast iron deck for durablilty. I take it you are talking about a 351 motor and intakes for them are cheap compared to the B.A. intakes and if your talking 302 those manifolds are all over the place. As for running aussies on pump gas I figure they will need hardend exh seats to deal with todays unleaded gas. If you really want to go with the aussies by all means go ahead they can run good, but I belive in the long run the modern heads would make you happier.

 

[Ray]

MM That may be but 70 has a Cleveland engine to start with and the original manifolds bolt directly to Ozzy heads do they not?If cougmanj is running a "W" then I agree w/you however I believe he was asking about "C".OK Catz yaz

 

[modifiedmark]

Ray, I should have went to bed an hour or two ago,my mistake, your right on. For some reason I read 69. The smaller 2v ports are better for most street apps and the compression will be increased with the aussies and the 2v manifold will bolt on. Still will need hardened exh seats.

 

[Ray]

Hardened seats

I am nearing sleep as well but have this to add I have logged mega miles on nonhardened seat heads with No problems so far.I think its a myth perpetuated by hardened seat companies to get our hard earned dollars.Theory was that the "dry" unleaded fuel would not lubricate and that the seats would end up on the valves.I work with these cars every day and though I do not say you don't need em I will say I have never had a problem without them.Here in Canada the seats are $20 each installed so probly about $100 for the US.69 "W"s were awesome engines for their time I currently am running one from 69 that was in storage 25 years and is the 4V 290 HP.Quite a noise when shiftin gears .Sounds like I run over a small yappy dog.Night

 

[cougarmanjr]

Thanks for the replies. I should have specified that my cougar currently has a cleveland in it. Otherwise, I totaly agree that there are much better heads on the market for the W's. I think that I will keep my eye open for a set. I came across a company that will ship them to my door for a decent price, and they have been showing up on eBay a bit. I also saw an add that sells ported and flowed, assembled Aussie heads for like $1200. May not be bad when you add all the machine work, labor and parts together over rebuilding a core set.

For my 347 buildup, I have a set of aluminum GT40X's that I plan on using (yeah, they may not be the best out there, but for $400 with low miles, I could not pass them up).

Thanks again.

 

[modifiedmark]

Ray, if you like your 69 w like you say I wish you could have tried my dart headed 13 to 1 377 inch w I used to have. Thats why I want to do a 393 or 408 next time.

 

[Cougrrcj]

Cleveland heads

OK, Cleveland history lesson here....

In 70-early 71 there was a 351C-4V that used closed chamber 4V heads. This engine was the 'M' engine code.

In late 71-74 (yes, 74!) there was a 351C-4V that used open chamber heads. This is the 'Q' engine code ( NOTE: not to be confuse with the 69-70 428 'Q' engine code!) This engine is also called the 351CJ.

In 71 there was also the Boss 351. This was a mechanical lift camshaft, Holley equipped, 351C-4V. This had a 'R' engine code.

1n 72 they detuned the Boss 351 and made what they called the 351HO. It was a lower compression Boss 351. (with some other canges as well.

Now, I'm gonna let you all in on a little secret. On a Cleveland 4V head, there are little '4's on the upper corners of the head, just outside of the valve covers. OK fine. Now, if you see a bump or pimple (about 1/4" in diameter) next to the '4', this signifies an open chamber head. If it is a '4' with no bump it signifies a closed chamber head.

351C-2Vs and other 351M-400s do not have anything on those corners. 351C2V heads are all open chamber except the Aussie heads which are closed chamber 2V heads.

Now to further confuse the issue, there are two different 351C-4V open chamber heads. The late 71 and 72 have large valves, while the 73 and 74 have small valves.


Hope this helps you Catz!

 

[cougarguy]

Hardened valve seats are not something you will probably need. The amount of time you drive your classic cat unless it is a daily driver do not warrent the mod as ford heads are notorius for their nickle content and are some of the strongest followed by gm. but if your running any pentastar stock be forewarned they use a softer casting process and you will wear them out quickly. but who wants to drive one of those cars anyways.

 

[dalerivers]

351C 4V Head Indentification

Cougrrcj...again an excellent lesson on 351C heads.

I finally got out and visited the fellow with the 351C 4V Heads and looked them over pretty carefully. They do in fact have the 4 and the 1/4" dia. bump by the valve cover. Does this mean that these are 351C CJ Heads????

When I flipped the head over on the underside of the Intake Ports was also casting info. The 1st port had a 2, the 2nd port had a D1AE, the 3rd port had a fairly large GA (underlined), and then the 4th port had the FORD emblem.

The only other identifying mark I could see anywhere on the head was on the underside of one of the Exhaust Ports and that had a 5 with a smaller pimple or bumb about 1/8" in diameter.

Any ideas on what I have here from this information or do I wing it....

Thanks for all your help

Dale

 

[Logan]

Intake valve on the head should measure 2.19 inches...

 

[dalerivers]

351C 4V "CJ" Heads

Thanks for the replies guys...I got the heads and Cougrrcj deciphered some of the casting marks for me to determine that the heads are infact CJ Open Chamber heads. Now I'm happy with that information and look forward to those puppies giving me Cat some ZAP! (or at least I hope).

Hey Logan, the valves measure in at around 1.75" and 2.22" or as close as I can tell without a proper caliper. Does that confirm things? Also found the casting mark on the top of the head (under the valve cover) which was "0M8". Now from the wonderful lessons I've learned here on this fabulous web site, I figure these were built December 8th., 1970. Sound right?

Thanks again for everyones help

Dale

 

[Logan]

Sounds good to me!

Now don't you think you'd feel better if you just donated them to me? You don't really need those big valves anyway...

Just as an aside, the intake valves on the 351Boss/CJ heads are larger than most big block intake valves... Which is an interesting tidbit