273 upgrade to 4bbl?

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BPTracing

BPTracing

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I picked up a really solid 1967 Dart GT with the original 273 (auto) with 84k miles. I have been driving it quite a bit and love it! ❤️ However, it doesn't have much power/acceleration. As time permits, I plan on upgrading to disk brakes, 4.5 bolt pattern wheels, and an 8-3/4 rear end. But until then I really don't want to do too much to the motor for now. I have been kicking around the idea of getting an edelbrock performer intake and small 4bbl to see if it gives it a little more "pep". The car already came with a dual exhaust system, so I figure the 2bbl is the main performance restriction currently. Just posting to hear if others have had experiences with this kind of upgrade.

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IMHO....upgrading to the new intake and four barrel will absolutely add some "spunk," as long as you don't overdo the CFM output of the carb you use. If it was my choice, since you have the intake off, pull the radiator and then the timing cover, valve covers and push rods. Pull the lifters, chain and the cam. Shop around and get a cam and lifter kit to match the type of performance you are looking for. The folks at Hughes (https://hughesengines.com/TechArticles/2choosingacam.php) are great to work with and can hook you up with what you need. The folks at Competition Cams are great also. BTW don't forget a new chain. Sounds like a lot of work, but it really isn't. Have fun and enjoy the outcome.
Norm
 
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There is a stock 4bbl manifold available on face book market place.

Next time I see it I'll get the link
 
Thanks Norm. Eventually I will get around to doing something more serious with the motor, maybe even a 6.4 hemi swap, but for now I don't want to take the motor down until after the brakes are upgraded, and probably a little cosmetic work. The car is currently a fun driver and looks great from 20ft away, or in the dark.
 
Dana67Dart said:
There is a stock 4bbl manifold available on face book market place.

Next time I see it I'll get the link
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I saw the stock one, but by the time I purchased it, and had it shipped, the Edelbrock was cheaper and makes more sense to me.
 
Ok....so I guess what I found was a chinese "knock off" of the edlebrock intake.....now I have to wonder if it is worth the $135 gamble or just go straight to the real thing......

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I believe that intake has the larger 340/360 port size.
 
Yep. That's a beauty of a Dart. A stock 4 barrel and a 500-600 works good. A 4 barrel and a distributor recurve will add some pep for sure. If you want to search for one the LD4B Edelbrock manifolds work quite well and are made for the smaller port 273 heads.
 
One factor that you’re not mentioning is what is the rear gear ratio? If your stuck with a highway gear, no 4bbl is going to give you a lot of power except when your getting up to speed. It will improve but not what you may be looking for. I would invest in the 8-3/4 first with a better gear for the street then go for the 4bbl.
JMHO
Syleng1
 
To be honest in my opinion there won't be a "drastic" increase in pep. SOME of the limitations are the 2bl pistons. We went from 2bl to 4bl(never drove it with 2bl) on our 273,(comp cam, lifters, timing chain), but cam was 340 sft cam so that's my fault. Not as peppy as I'd like, your results may vary.
 
If it was me, I would limit the $$$ spent. It will still be a 273 & there is only so much you can do without going to power adders.
 
Bewy said:
If it was me, I would limit the $$$ spent. It will still be a 273 & there is only so much you can do without going to power adders.
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Well ya, it's like a teen. How much can you do without building a performance specific engine. With a 273, a 4 barrel will help. so will a distributor curve. (probably the biggest improvement for the lowest dollar invested) A HP single exhaust or a dual system will help. A steeper rear gear won't add horsepower but it will make it spunkier or faster. We all know the next step with the hipo pistons, bigger cam, ported heads, and high stall converter. This has been discussed to death.
 
Bodyperson said:
Who says the "world" is correct?
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It must work or everybody into making horsepower wouldn't be doing it. Run a 340 manifold on 273 port heads. Your choice. It will work just not optimum. Your idea isn't anything new.
 
toolmanmike said:
It must work or everybody into making horsepower wouldn't be doing it. Run a 340 manifold on 273 port heads. Your choice. It will work just not optimum. Your idea isn't anything new.
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I agree. AND i think the port mismatch is not as big of an issue as most make it out to be.
 
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