A friend of mine and me would like to improve the power of our slant six engines equipping our Spanish Dodge 3700GT. It´s a 225 cid rendering 165 H.P. DIN with a Carter BBD 4300S carb. The car goes fairly well with her original equipment, reaching 120 mph before disintegrate and 0-60 mph in 12 seconds (manual 4 speed gearbox) but we know the engine can give us more with little more effort.

Is there a power pack easily available and ready-to-install in the market?

In Spain we have never used upgrading kits on this engine but in U.S.A. there must be a lot of possibilities. Which one is the best combination power/reliability?

if we could order it by Internet it would be great

You can see below some pics of my all restored engine Dodge 3700 GT '73 automatic torqueflite A-904 (blue) and my friend´s '75 4 speed manual (champagne) -Just 22.000 miles-.

the A/C pump are the big power drain but you need them with your heat. what cam and compression are in your engine to be at 165hp level?

sweeeeet

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

It looks like you already have the equivalent of the "Super Six," which was the hottest easily obtainable version from the factory in the US. (I've heard export market ones used a different intake manifold.)

Usual hop up strategies would be to run a mild cam upgrade, a 390 cfm four barrel carburetor on a Clifford or Offenhauser manifold, mill the head a bit for more compression, and run either one of Doug Dutra's split manifolds or tube headers.

The US market for performance parts on this engine has stagnated a bit - most of the parts made here were designed when these engines were new. There's some interesting new parts coming from Australia lately.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

first off you could have an emissions friendly compression ratio of 8.5:1, so i'd recommend looking for a machine shop to plain the head and then you can recurve your distributor to get 10:1 or something.

Samething for the camshaft, i would go to www.summitracing.com and look at camshaft/lift packages to help your slant breath deeper.

The rest falls into oversized valves, porting/polishing the head, bigger ignition power, headers, and making the engine strong enough to handle all this comfortably.

But the most important thing you can do is ask on these subjects from more experienced members on this forum than myself :p

Yes, I like this pic a lot too. Me and many other friends think that these cars are somehow hypnotic . I can be just staring at her 1 hour without even noticing the pass of time. Maybe it´s the balance between american line and european trim when it was designed. In a country like Spain where such a low number of american cars arrived, it was called by someone "the Spanish Cadillac" (A real Cadillac could be considered a Starship )

I do not know what cam is in this engine. I only know that automatic version has a different cam than the manual, allowing more power to compensate loss of performance. If we put my cam in my friend´s engine (manual shift), he would notice.

The compression is 8,4:1.

I will check if there is a photo when the engine was disassembled. I think that we never took it out of its place.

¿How many H.P. do you really think the A/C pump is draining from the engine when A/C is off?

Very interesting!
How much do you think we could increase power with a 390 cfm four barrel? And with one of these manifolds?

Interesting. Do you think you can find the camshaft specifications, perhaps in the service manual?
Zero.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Have you conducted measurements to verify the compression, or is this the compression listed in your manual?

I'd check first.

8.4:1 is pretty low to get much, if anything out of a 4 bbl installation. Shoot for 9:1 or better.

Without pulling the engine down, checking how far down the hole your pistons are, and measuring the combustion chambers, it is difficult to determine just how much compression you have. There were some pretty large variations from one engine to another.

Find out where you are, bump the compression up as necessary, and look into options to increase exhaust flow. Choose a Cam that will fit your intended use as well.

Are you planning to race the car, or just want a little more zap around town? A higher stall converter can go a long way to improving acceleration. You are likely to impact bottom end power with a larger carburetor, so may find you will need to address the converter anyway.

CJ

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Part of Tyrde-Browne Racing

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Great idea!

I´ve got the workshop manual and the parts and timing list manual. I´ll see which information I can get from them.

What a lot of ideas!! Yes, I´ve seen that there are several cams at summit racing for the slantsix. As you have gessed I have a compression ratio of 8.4:1.

The idea of a bigger ignition power seems interesting. Any tip on a particular equipment? ignition coil+distributor?

How much power could I get with this last solution (It seems easier than plaining head or change valves)

It's a better idea to get a slant-6 cam through Erson, who sell cams specifically designed for the slant-6 rather than old "generic" (usually Chevrolet) patterns on slant-6 blanks of varying quality.
HEI upgrade

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

if your going to try the ersons deal you will need help getting it shipped to you, they can`t ship out of the u.s. but it is a good deal