Originally Posted by surfsup
Any one running a dual quad set up on a 289 302, thats pretty much stock,,everyone thinks I’m nuts, but there’s something about two fours sitting under the hood, I would really like to go that route if possible, and I’m not really sure way I can’t when ford offered this set up for the 289 mustang back in the 60’s as a increase in horse power, and I believe they only had around 250 HP, I believe with my e cam ,gt 40 heads, long tubes and cat back, I should be around 350 + HP
Great question. For you to do it, you definitely need a cam that makes power between 2,500-6,500 rpms. Otherwise, you won't take full advantage of Edelbrock's intake manifold which makes it's power in that RPM Range. The GT-40 heads will be fine if they're ported well and have larger valves installed. We used solid lifter cams and Edelbrock 500 cfm carburetors (with two tuning kits!) This setup will not pass emissions so if you want it in a later model car, you may not be legal. Also, these combinations usually lack in the torque department, requiring steep rear gears (we use 4.30's.) That being said, let's get down to the nitty gritty.
My twin brother Retro 5.0 posted earlier about his dual quad setup. It is extremely streetable and is right at home on both the street or the strip. As he stated, it made 311 rear wheel horsepower and 287 rear wheel torque and runs 12.40's-12.60's @ 108-110 mph (on ported/polished/larger valve '69 351W heads.) Here's a pic of his engine.
How do I know about it's street manners, power and driveability? I copied his combo for my own 'Stang. I was so impressed with it's manners and more impressed with people's reactions at the local cruise nights, I decided that I had to have that too. Imitation is the sincerest form of flattery, right?
Anyway, my engine differs slightly due the the fact that I have an Edelbrock dual quad intake manifold vs. his '60's era Offenhauser unit. I also bought AFR 185 (58 cc's) aluminum heads and I have a slightly larger camshaft. We decided that it was easier and less labor intensive to buy the heads already done and to add a bigger cam to take advantage of the additional flow characteristics. We learned a new lesson along the way. His engine made the 311/287 numbers (smaller cam/less flowing heads) while mine made 307/278 (larger cam/higher flowing heads.) It's all good though! Mine runs 12.40's-12.80's @ 107-110 to his 12.40's-12.60's @ 108-110.
Here's a pic of my engine.
Here's a pic of the two together.
As everyone knows, street cars MUST be driven! Each of our cars runs on 93 octane with no detonation and the temp guages are at 180 degrees (rising slightly in traffic). We have driven them numerous times to Connecticut and New Hampshire (2 to 2-1/2 hour ride each way.) Even beating on them at the track in New Hampshire and then driving home.
Here's my dyno sheet. I don't have my brother's to post, sorry! As you check it out, look at the power curve. My cam makes the power from 2,400-6,400 rpms, right where the intake makes it's power. The air/fuel is very good as well.