66 - 273

[RioGrandMan]

Good morning all,

So I recently got my first car back, a 1966 barracuda with the stock 2 barrel, 273 (but the prior owner bored it out to 308). I'm planning to swap the heads, cam, and intake, add a 4 barrel and headers to build up the numbers matching block. I hope to not trim the inner fenders for the headers and keep a stock look for the car where possible.

Any tips or advice on this project is welcome at this early state appreciated.

Rio

 

[66fs]

Keep the heads, they flow the best for what you want. Get a competition valve job, and use stainless steel exhaust valves. Use a Custom Racer Brown cam or an Isky E-4 will work nice for an off the shelf cam. Skip the headers, just run the 66 Commando 2 1/2 exhaust with your manifolds. Delete the heat valve on the passenger side manifold. Stock 4 barrel manifold and carb or aftermarket 273 or 318 intake with a Street Demon 650 cfm carb.

 

[pishta]

numbers block is a myth on a 66. There are no VIN stamps anywhere. Just get it close date wise. But you have it already so your good. 66 is a good year for mods as it will take a 'normal' LA intake but if your looking for 'numbers', youll have to find a 273-4 intake from a late 65-to mid 66 year date coded intake. 66 year was manufactured from about Aug of prior year so a 65 dated intake will work IF the bolt angles are correct, ie there are no wedge shaped bosses on the intake bolt holes that would bias the thinner 5/16 bolts toward the crank center line. Your looking for flat bolt bosses that go straight through the intake flange. Get a modern cam that will take your lower compression into account. The stock 273-4 cam was designed for the higher compression of the 4bbl pistons used in any 273 block, they did not change. You got 2 or 3 choices for chassis headers, Dougs, Ed and TTI. Make sure you get the 318 port sized headers, 340-360 flanges will not seal. AS stated headers are not the most practical upgrade her on a mild build. Just use the larger Y headpipes and Formula S type exhaust as it was a pretty good design.

 

[66fyssh]

IF you go with headers, I recommend Doug's. They fit nicely. Use a mini starter off a mid 1990's Mopar truck. I also clocked my 90* oil filter adapter slightly different.

But...like others have said, just keep the factory manifolds and go with a 2.5" dual exhaust and some high flow mufflers.

It's really cool that you got your first car back!!

 

[toolmanmike]

Good morning all,

So I recently got my first car back, a 1966 barracuda with the stock 2 barrel, 273 (but the prior owner bored it out to 308). I'm planning to swap the heads, cam, and intake, add a 4 barrel and headers to build up the numbers matching block. I hope to not trim the inner fenders for the headers and keep a stock look for the car where possible.

Any tips or advice on this project is welcome at this early state appreciated. I will also be in the market for an original air cleaner that fits a 4 barrel.

Rio

Nope! a 308 would be over-bored more than .200 (200 thousandths)

 

[cudamark]

You're planning to swap the heads to what? Does it have the original 920 castings? If they're not cracked, they're not a bad head if you can run high enough octane gas for them. The later open chamber 675's seem to be less trouble prone, but, they'll lower your compression ratio a bit. If you're putting in new pistons, that can be overcome. The late model 302 casting are also a good head for performance and mileage, but, you have to plug the smog holes and do a bit of grinding on the driver's side to get a stock exhaust manifold to fit properly. If you're keeping the stock 2bbl pistons, don't over cam the motor. The stock 4bbl cam or slightly less will work fine. I have a .435/.435 Isky solid cam on a '68 2bbl engine with the stock '66 4bbl intake and exhaust manifolds, and it works fine. No need for headers with that setup.