I have a stock 289 in my 1966 convertible-I am getting another 289 from a friend to use as parts.I have been thinking about turning the doner 289 into a 302.I have never done anything like this before but I thought it might be a fun project and eventually pull out the 289 and put in the 302.

Questions:
will my 8 inch rear be okay with the 302?

what will I need to change-the engine will need to be bored out, new pistons,change the cam and add a new intake manifold with a 4v carb....is there much more to do?

I am very limited and this is new to me, but with the help of some friends I thinkI can do this....and I want to add headers too...
how much $$$(estimate) amI going to put into the 289 block to change it to a 302.?

Is there a step by step directions on the internet anywhere for the conversion

WouldI be better off saving the 289 and just buying a 5.0 ?
Thanks in advance for any input Scott

 

I'm really no 289/302 expert, but I think you don't need to pull the engine - all you need to do is replace it with 302 heads.

 

I have heard that the 289 cylinders are slightly shorter than the 302 blocks, there is conflicting opinion as to whether this will affect the longevity of the engine when this is factored into the equation, when going to 302 ci.

I have read that Ford used some "left over" 289 blocks in the early 302s, so I dont think that this is really an issue, but others will certainly disagree.

To convert the 289 to a 302 you will need pistons, rods, and a 302 crank.. I can't remember if balancing is an issue or not, if so, you will need a new harmonic balancer (advise a new balancer in any case because it is very old) and a proper balance fly/flex wheel.

Your 8" will be fine, and below are some links for a couple of books, this will be required reading for you...

http://www.amazon.com/Rebuild-Small-...684066-7003268

http://www.amazon.com/gp/reader/0912...68#reader-link

 

http://store.summitracing.com/egnsea...splayPrice%7C0

Here are some rotating assemblies from Summit, for a 331, they don't list anything for going back stock as a package, but since a 302 is a "stroked 289, might as well go to 331 anyway....

Here is another link for The Mustang Depot, they are cheaper, check out thethird item on the page, you can go 302 or bigger.I bought my 408 kit there, they will work with you over the phone to help you get what you need.

http://www.themustangdepot.com/servl...its/Categories

The advertised price on this one is $590.00,, 306, 331, 347 all the same price...

You will need a 50 oz imbalance flex/fly wheel, 50 oz imbalance harmonic balancer, you will need to have the assembly balanced, (+200.00, seller can do this) and you will need the rest of the components to do the rebuild, cam, gaskets, oil pump, machine work, cam bearings, timing set, etc.

IMO, if you do the work yourself and don't change heads, you should be able to do this for about $2,000.00 total, maybe even including the headers.

 

Personally, I don't think it's worth it at all unless you've got a 302 with a junk block. The power difference between the two is negligible and not worth the money you'd spend buying a crank and rods.

However, if you do want to increase displacement, a 331 or 347 would be much more cost effective.

289 and 302 blocks have identical piston skirts. I've talked to a guy who actually mic'd a 289 and then a 302 block to compare; no difference. And I've got my 289 block stroked to 331 and have no problems

 

Yeah, crank and rods, plus whatever pistons work. A 302 can be made from a 289 without any problems, a 331 might be a good choice too

 

What are the advantages to rebuilding a 289 to a 331? Does the boring impact the life of the block. How much horespower do you gain? Is it that much more expensive? Looking at the stroker kit from the mustang depot. Currently a "c" code engine. Will be changing the carb and the cam too.

Thanks,

Fred

 

Advantages are more power! Horsepower will vary depending on agressively you build it. Same with longevity of the motor. My 408 stroker is a daily driver.

 

Depending on who you ask, you can only bore the block .030 over anyway. All of the standard kits will be for .030 over-bores.

Some say the blocks can go to .060, I would probably find myself in this group.

If the block needs boring it will need to be bored regardless if it is built as a stroker or not. Stroking an engine will not effect cylinder bore. You can expect to gain HP and torque to an amount equal to the increase in displacement, or about 10% from a 302 to a 331, or about 14% from a 289 to a 331, all things being more or less equal in price if not exact specification.

 

It's not the bore that gets you the extra displacement, it's the stroke. You need a special crank, rods, and pistons for a 331, and probably some light grinding on the pistons skirts to clear the rod bolts.

I build a 331 for my 67fb and I love it. It's enough extra displacement to make power a little lower down the rpm range than a 289, but not so much stroke that it abuses the piston rings and cylinder walls (like a 347).