Hi all,

I'm looking to upgrade the 289 in my '66 Fastback. I'd like to get to 300 - 350 horses using the optimal components available today. Assuming I'm starting with a complete stock engine what would a "perfect" spec be? I realize there will be many opinions on this butI'd like to hear what you think. My goal is to select each component very carefully so I make the right decision first time round.

Comments on carbs to exhaust system much appreciated. My goal is to have an original looking carwith some guts under the hood.

I use my car as a weekend driver so I want a good balancebetween power and practicality.

Thanks

 

well, like a few guys on here have stated before, safety should be done first. i would say put some money into suspension and brakes. power discs in the front are great and maybe some suspension upgrades (new leaf sprigs, shocks all that good stuff). as for motor upgrades, you gota look at the whole aspect. finding outthe right combination of certain parts is what gets best results.

300 hp goal out of a 289 is not hard to get. some performance heads, cam and intake will most likely get you there. a nice 4bbl carb would be good too. im notreally gona get into detail about carb size and cam lift etc, i guess it depends on what your going to use the car for and how often. (more of your preference)

also if your going to be pushin 300+, i would say get a posi third member with maybe a lower gear ratio, thats makes a world of difference.

if your still using the c4, then i would suggest beefing it up a litte. maybe kevlar bands/clutches, a diff vavle body, shift kit etc..

and exhaust, what ever you get is fine. as for headers, i personally like tri y;s, they are great street headers.

 

in terms of exhaust my personal favorite is flowmasters. youtube it, they sound great.

 

i love my super 40s! lets my cleve breathe real nice.

 

Just to add an opinion, I generally do not like the sound of 40-series Flowmaster mufflers. They're obnoxiously loud, and everyone has them. I've got a set of their Hushpower II's and I love them. They don't drone like the 40's generally do, they're not as deafening inside the car, and they sound incredible, especially above 3k. They're expensive, but I think they're worth it.

Outside of Flowmaster, one of my friends has some Dynomax mufflers on his Chevelle that have a really nice tone to them.

 

Thanks for all the info. Re the headers I think I'll go for tri-y's. Didn't the original Shelby GT350's come with tri-Y's? Also, what about pipe size? Is 2inch ok for a 289 or do you recommend something larger?

 

I like the Ford 4100 carburetor and stock manifold. The carburetor is reliable and belongs on the car. IMHO If you're going to drive a Ford it should be a Ford. The GT40 heads are much better flowing than the original ones and are again Ford. I'm sure Ford has the right cam too.
Upgrading to a dual master cylinder is an easy, inexpensive safety improvement that will let you tap that 300hp with confidence.
Doing the Shelby drop and adding a bigger front sway bar in conjunction with new rear springs and poly bushings will also give you much better handling.

'66 Fastback cruising Boston.

 

Have a look at the edelbrockRPM power package. It will get you where you want to be, with proven results. You "could ' select some different component to give yoi a slightly better result, but Edelbrock has done all the work for you.

 

Yes, the 65-66 GT350's came with tri-y's from the Shelby plant. For a 289, 2-1/4" pipe should be just fine. More than that is overkill, unless you're spending a lot of time at high revs.

While I generally like the Autolite 4100 carbs, I wouldn't use one on a 300hp 289 build. The stock 1.08 model is ideal on a stock engine, and the 1.12 version works well on slightly modified engines, but I'd want something more tuneable for a serious power build.

I definitely have to recommend against a factory manifold. Cast iron is HEAVY. You can easily shave a good 30lbs off the front end by switching to an aluminum intake, and unlike the factory cast manifold,it will support the increased rpm range that will be required to make all that power.