[whizco]

Yea I know! Not another 351 Head swap question. I did stay up to 3am searching the forum and the net and found a wealth of information. One thing I did not find was what the "actual" gain I would have over a stock set of heads on a 289 engine.

I know they have bigger valves and ports, an I also know the compression suffers because of the larger cumbustion chambers. Also that removing the bump in the exhaust port will help with the flow, and a the variety of ways of mounting them, etc. etc. What I haven't found was what kind of gain they actually got "after" doing the swap?

I have a set of 69 351 heads I am considering putting on my 66 289. If I do, I will have the heads milled to reduce the chamber volume to as close to 54 cc as has been suggested to increase the compression. I am not tearing the engine down, so replacing the pistons is not even a thought. If I use the 1.9 & 1.6 Chevy valves, will I need to use shorter pushrods to accomodate the Chevy valves?

The 289 engine has been bored either .20 or .30 over prior to me buying the car. I have a set of shorty headers, and will be adding 2½" exhaust with a "H" pipe. Also will be using the Pertronix II and Flame Thrower coil. I'm also thinking of using a Torker-Plus cam, or something similar to those specs. And yes, I will be using the Edelbrock dual quad set up I recently obtained, and no I won't sell it for a single carb set up as has already been suggested.


So what kind of gain over the 289 heads will I see in extra Torque & HP?
JohnPro, Camachinist, Anyone?

 

[390GTAcv]

Doug ; one thing to really pay attention to is port matching on the intake side.

 

[whizco]

Yea, I noticed that during my searches, just forgot to mention it in the post above!

 

[TheShagg]

Why does it matter if your selling it?

 

[mlnielsen]

Here is some more data...

Cylinder Heads Comparisons

Head to Head! Flowtesting

The Ford Small Block Head FYI

 

[whizco]

It matters to me! Why should me selling it mean I have to settle for just slamming it together, throw a maaco paint job on it and be done with it? Sure I may not make as much as if I were to just slam it together like some do, but it's not always about the money, at least in my book... If that be the case, then I guess I should not worry about the custom interior with aluminum inlays retro to 67's in which I have been working on for about 6 months in designing and building, or the vintage 37 year old original Top Eliminator wheels I found and restored for it, or some of the other one of a kind parts I am having especially built for it, etc.

I own 20 cars!, it's not always about the money, sometimes it's just for the knowledge I gain and the sheer fun of it! Try it, you might like it.

 

[sfv]

your right,it's not about the money.MAKE IT RIGHT!!!I need to know what the casting # is.The best heads are c9oe-b,d,or c.They have a 60 cc comb. chamber.With 1.84 int. and 1.54 ext. these produce about 45 hp on a stock engine.Cut them 20-40 thou.. and your comp. is about the same.Do match the ports if you can.They work great.Look for an "L' shaped water port on these heads.That gives them away as to possibly being the right ones.SCOTT 936-756-2535

 

[whizco]

I don't have the casting #'s in front of me at the moment, will try to pull them out of the rafters today or tomorrow to check. but if it helps, these came out of a H-code 1969 Cougar 351W 2v

 

[TheShagg]

I AM trying... i thought everyone knew that

 

[2ndNatr]

Doug -

I can't tell you any actual performance increases (no dyno #'s) nor seat of the pants increases either. But what I can tell you is those heads, with a decent intake carb (read Edelbrock Performer 289 and Edelbrock 1406 600 cfm), with a Performer cam - and stock log-type manifolds and the single factory V8 exhuast system - made the engine performance suck bigtime!!

My guess are headers and dual exhaust would really wake the beast up. So don't put together the same combo as I, if you want the 351W heads to make a difference.

Sorry I can't tell you more.

 

[mstngjoe]

....The best heads are c9oe-b,d,or c.They have a 60 cc comb. chamber.With 1.84 int. and 1.54 ext. these produce about 45 hp on a stock engine.....

First time I've heard that number. Sure would like to see the before and after dyno sheets on that.

Even if you mill the heads and get your compression back up, you're still dealing with stock cam, intake, carb, exhaust. How do you take advantage of the extra flow capability of the W heads without upgrading the other components???

 

[TheDude]

Try it, you might like it.

What...owning 20 cars? Yeah, I might like that.

 

[whizco]

Try it, you might like it.

What...owning 20 cars? Yeah, I might like that.

Hehe! I meant having fun with what your building! I think folks sometimes loose sight of why they started their projects in the first place because the money thing get's in the way. I try to look at all projects whether I'm doing for myself or to sell, as a learning experience and enjoyment! If the enjoyment part of the hobby ever fades, I figure it will be time to get a new hobby.

 

[johnpro]

I can't say for sure how much the 351w heads alone contributed to the performance of my engine. When I put the 351w heads on my 289, it was a brand new engine with new Lunati Bracket Master cam, 10:1 KB pistons, and a host of other new parts, including the AOD transmission, so it's impossible really to compare it to my old engine/tranny combo.

I didn't port/polish my heads, which I know was a mistake, but I was beginning to get pressed for time in getting the car back together.

I will say, that they seem to be just fine on my daily driver. Best run to date was a 14.334 at 96mph and that was spining one tire (haven't fixed the traction-lok yet) through half of first gear.

My car definately will plant you in the seat when you take off. How much of that is the heads, I'm not sure, but the car is fast enough for a daily driver for me. If I had to guess, I'd say you'd pick up about 10-15 HP from the stock 289 heads and you WILL feel it in the seat of your pants, especially if you port the heads.