67' 300 440 to 500HP

Cortez

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So planning my big boy engine build and need some guidance from the Vets. So i have a stock 440 with original 16k miles and sitting in the garage for years. I currently have an aluminum radiator and Quick Fuel Brawler 750 on the stock intake and dual exhaust with Super 44 Flowmasters. She runs damn good. So I will drive her this year and plan my build. The goal is 500 HP or close to it following the Motortrend build, my question is what other upgrades to the car must I do o be safe and efficient with the added horses. She currently has newly rebuilt 4 wheel drum brakes and I guess stock 300 convertible gearing. I am open to any and all suggestions. How You Can Build a Stout 537HP Street 440

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I would consider using an electric fuel pump setup with an adjustable fuel pressure regulator. An upgrade to front disc brakes and a drive shaft loop for safety. Use a separate, radiator style transmission cooler and a deep transmission pan with the appropriate pickup. Use an ignition system with a rev limiter. These are some of the things I did when I put a 520” striker in my’68 Sport Fury.
 
Might better start with a 2-dr sedan or hardtop rather than a convertible . . . unless you are willing to put a frame under it. Body flex under torque is not good for any unibody, especially one without a top.

NOT to forget rear leaf spring flex/deformatioin under high torque. Look for some old Traction Master traction bars, rather than the slapper types popular on Camaros in the 1970s.

I suspect you are "itching" to tell everybody how much power you car will have, BUT 500+ horsepower at 6000rpm is not going to untrack it at 2000rpm. Focus on TORQUE, which actually spins the rear wheels, instead. Tell everybody how many sets of rear tires you've bought because it has so much low-end torque. Or how you had to have a special driveshaft built to take the torque, plus special u-joints in it. Or how you spent $5K on getting a TorqueFlite built to handle that much power.

Get a new, quality top on the car. Get it polished and waxed and shined up, so it looks good. Consider spiffing-up the seats too, so it all looks nice and enticing to ride and drive in. THEN enjoy it! Save your money . . .

Respectfully,
CBODY67
 
I gotta go with Cbody67 on this one. In my own opinion, spending large $ for added horsepower in a big convertible is not a very efficient use of your funds. These cars came with a significant amount of power from the factory, and were meant to cruise down the highway with the wind in your hair, not burn the neighbors Camaro from light to light. (Although they will do that too!) These cars have a lot of flex. On top of the engine build, expect to tie together the frame, upgrade driveshaft, major transmission work, u-bolts, rear end, all suspension etc etc.
If you notice in the link you provided, they were going to put that engine in a Duster or Demon or something, not one of our whales! They also added headers at the dyno shop, a huge cam, a high rise intake manifold (cut a hole in your hood) and big *** carburation . If ya wanna build a 500 + horse street brawler, get a Dart or a Satellite or something similar and go beat the tar out of it!
Big drop tops in nice condition are getting rarer by the year and yours looks like it has lots of potential. IMHO I would spend the money you are looking at here, (something like $12 to $15,000) on making yours really nice, and just do a quality rebuild on the existing motor with upgraded pistons, heads, intake, carb, timing chain, oiling system, exhaust etc. It will be fast, reliable, and top down to boot! These are only my thoughts, but having just finished my 67 drop top (well almost!), I like where I am at. I also had the luxury of a group of Mopar fiends and friends who helped me make decisions along the way and avoid costly mistakes. Here is my 440 TNT all done. Moves the big boat along at an impressive rate. Scares the hell out of my wife! All good!

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I wouldn't suggest following that Motor Trend article unless you also go with a much looser torque converter and shorter rear gears. 500 hp is pretty easy with a big block but if you want to keep it as streetable and cruise like it does now you'll need to increase displacement for sure, or go with a power adder. The single plane intake and large duration cam isn't going to work well with highway gears and a stock converter.

I wouldn't personally bother with an electric fuel pump though unless you go EFI. Using the Carter street mechanical on my 440 and it's more than adequate, I know guys running low 11's with them.
 
So after a little more research I did confirm that adding massive HP in a vert is different than in a full body..I will take the advice and spruce up under the hood without going full drag race and enjoy a reliable street machine with a bit of sasss. I have an upgraded aluminum radiator and a new carb Brawler 750 and got the stock intake powdercoated, I also rear built the drum brakes from drum to master cylinder lines included. My question is now what additional areas need to be addressed for my lady. The tranny is leaking from the front but I'll do the seals and filter as I think it is from sitting so long. She has 16K original miles but has been garaged for the last 15 years.

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