289 rebuild query

['66GT]

First post here ...

I'm going to start rebuilding my '66 GT 289 A-code. It's been sitting for over 2 years, so it's time to get it working. I have $3000 Cdn (about $2200 US) to go towards parts, machining, and outside labour. My uncle will be assisting me with most of the labour to make sure things are done right. I only know a little bit about engines, so I thought I'd start by asking a few questions.

Some info: As it is nearly all stock and original, I thought about keeping it stock. But if the rebuild requires replacing a few things, then I might as well build it up a bit. The car will only be used in summer as a daily driver, and if I need to I'd also like to be able to fry ricers with it . Right now it's got a 600 cfm Holley, tri-y headers, 4-speed manual (also needs a rebuild), and 3:55 gears I believe.

Without taking away from the engine's stock look too much, I would like to generate 275 - 300 hp. If I kept with stock pistons, where would be a good place to start: cam, cylinder heads, valve train, intake, others? Should I also consider exhaust at this point?

 

[Ronstang]

To make good power you are going to need good heads and a good exhaust. You can use a ported set of early 351 Windsor heads to make the amount of power you desire or you can simply paint a set of aluminum heads for the stock look. On your budget I would suggest a good set of older aluminum heads since there are so many of them floating around and they will make the kind of power you desire at a bargain price.

 

['66GT]

Thanks Ronstang for the info.

I've got some newbie questions ... I took band instead of auto mechanics, so please bear with me.

1. How do 351W heads make more power? Do they have larger valves or is the CR higher?
2. What else should I consider replacing in order to get them to work well (pistons, valve train, cam, others)?

Thank you much for your replies.

 

[Ronstang]

The early 351 heads have larger ports and larger valves thus they flowmore air which is what you need to make more power. With a 289 the 351 head will result in a slight lowering of the CR so getting them milled would be in order if you want to keep the CR higher but all the aluminum heads would also require this machine work becuase early 289s had pretty small combustion chambers. You can also use a slightly domed piston to keep the CR where you want it. My suggestion is that you contact a machine shop that you trust and let them help you figure out all of these things since they will have access to all the info needed.

 

[66P51GT]

Ask the machine shop if the cylinders can get by with just a honing rather than a rebore. This will allow you to keep your stock pistons and save a few $$$. Additionally, when you have the engine pulled apart, have the shop install some ARP rod bolts in the connecting rods. They are only about $45 and is good insurance in the upper RPM range. There is no need to replace the connecting rods. The early 289s had good forgings and with the ARP rod bolts, will easily support 6500 RPM operation.

Another option for heads is searching the classified ads here at Stangnet and on The Corral. I picked up a set of iron Dart Windsor heads for $600 that only had ~100 miles on them. Ebay is another good source for picking up new/used heads but you will usually spend a bit more with less bargaining power over the classifieds.

If you have the original Autolite carb, you may want to consider a rebuild rather than a replacement. Otherwise, Holley and Edelbrock both have good options for vacuum secondary carburation.

Make sure your intake matches your cam specs. For a milder cam, look for a dual plane manifold such at the Edelbrock Performer. For a street/strip profile, look at a dual plane hi-rise such as the Edelbrock Performer RPM and Air Gap. Look a single plane manifolds for peak HP gains on the top end. You will sacrifice some low end torque so they are not the best choice for a mainly street driven car.

Exhaust can be mild to wild. For your HP, you can go with either a 2.25 or 2.5 dual exhaust. Going to a 3" would rob your engine of low end torque. As long as you replace the stock iron exhaust manifold, either a tri-y or 4.1 design will be fine for you. The tri-y is better low end torque vs. a 4-1 design which frees up some upper RPM HP. You will want to have an equalizer tube installed. This can either be a H or X design crossover. Choice is yours. Too many theories to which is better than the other. I typically pick mufflers for sound vs. power gains. In a recent article there was only a 2% gain in HP from one muffler to another.

I'm looking for a bit more HP than you but this is what I have in the works:
289ci. - honing cylinders, New Rings, New Rod Bearings, New Crank Bearings
Shot-peen connecting rods - install ARP rod bolts
Dart Windsor Jr. Heads (iron)
Comp Cams XE274 (274/286 230/236 @ .050, IN .487 EX .490), Rhodes Lifters, Roller Rocker Arms
Performer RPM Intake, Holley Street Avenger Carb (670cfm)
Mac 4-1 Exhaust Headers, X-pipe, Flowmasters Delta 50s
MSD ignition, MSD billet distributor, Blaster II coil, MSD wires
Holley fuel pump, steel braided lines, Edelbrock Victor water pump
All necessary gaskets, installation hardware, Motor mounts

I shopped for the best deals I could find for four months. Have everything ready to install with 300 in labor for for $3000. You can save $400 by installing pertronix vs. a complete MSD ignition. Save another $100 by going with a stock water pump. Save another $300 by rebuilding your stock carb and that would keep you within you budget.

$0.02