Carb, Manifold and Exhaust Recommendations

I recently found stack of hundred dollar bills and I finally got permission from The Missus to do a stack of upgrades that were needed.

We're talking about a 67 Country Sedan with a Z-Code 4V 390 10.5:1 comp (a generous 315HP from the factory, apparently), with a 3:00:1 rearend and single-tube-exhaust.

A new exhaust, intake and carb are in the immediate plans, with shorty headers and a lower posi rearend in "stage two".
(when I find another stack of hundred dollar bills).

Basically, I'm looking for good street performance, not to be king of the strip or anything.

Also: it currently seems to demand premium fuel...how hard would it be to tune to run on 89?

I've got a line on a Carter AFB 625 CFM carb.

• Don't know much about Carter carbs (or any carbs for that matter)...are they any good?
• 625 seems a little small for this beast...but then again, people tend to over-carb.
• For street (and occasional flooring on the on-ramp) use, what would you recommend?

What would you recommend for exhaust tubing diameter?
I'm thinking 2.5"

Lastly, I'm looking at dual-plane aluminum intakes...either Edelbrock or FoMoCo.

Pulling 100lbs of cast-iron off the top of the engine seems like a good idea, and dual-plane intakes are the better bet for street performance, yes?

Thanks for helping a newbie out.

I went with the eldbrock performer but it's not much better than stock but it is lighter. For power for the buck I would say get headers because the stock exhaust logs on the stock 390 is the most restrictive part and at least 2 1/2" exhaust pipes with a crossover pipe and less restrictive mufflers.
IMO!

Carter is identical to Edelbrock. Or, I should say that Edelbrock is identical to Carter, since Carter came first. 625 would probably work well for the street. I had a 650 on my 390, and it gave great throttle response and decent flow.

The only real way to reduce octane demands is to lower compression ratio, which basically means new pistons or heads with a larger combustion chamber. Either way, you're looking at big money there. Besides, premium gas is hardly any more expensive than regular. I don't know why people get so worked up over it. IMO, the increased performance provided by higher compression is well worth the slight increase in fuel price.

I agree with 64Ragtop on the Edelbrock Performer intake. It's basically a stock intake, except made from aluminum. The weight savings is nice, but you'll need a RPM model to see much flow difference.

Of course, your carb, intake and heads could flow 10,000 cfm, but FEs are majorly choked by the joke of an exhaust manifold they all have. Go with small-ish primary headers for the street. No one makes them smaller than 1.75", though, and that's pretty big for the street. To be honest, I'd do the headers first. They're the weak link in the chain.

Next, I'd put in a dual-pattern cam. The stock cam sucks, and FE engines need help on the exhaust side.

You're right on track at 2.5" exhaust.

If you don't mind my asking, what will you be doing with the stock 4bbl carb?

I have a 68' Gal 500 390 2bbl w/10.5:1, and a couple years back I got an orignal FoMoCo intake and am now just looking for a carb.

And doing a good exhaust makes a world of differance. I replaced my stock single with a true dual and it made a HUGE differance. Headers will be along soon, the same people that did my exhaust said they can make me a set that will go perfect with the exhaust.

For before and afters of the exhaust see here
Index of /tien/Exhaust

68Sedan500:
OEM 4V needs a rebuild (leaks gas and whatnot). From my cluelessness I can't really guarantee it's not an Autozone re-manufactured unit or something.

But it's yours for shipping and a minor contribution to my beer fund if you want it. PM me for details.

BTW, what did your exhaust cost?

Everyone else:
Thanks for the assorted advice.

Seems like a set of shorty headers would be a better investment than a new intake. Sanderson has a set that looks like it'll fit with column shift AT and power steering (there's not a lot of room in there):
Sanderson Headers

Figure out how much shipping from there to zip 13760 is, and how much beer moneys you would like and I'll let ya know.
Are there any apparent problems with it other than needing a re-build? Such as cracks or anything that is not fixable?

The exhaust cost me a little over $200, with each Glasspack about $30. Well worth it. I still can't stop my self from just reving the thing just to hear it. Sounds so great.

Yeah....can't wait on my exhaust. I figure if I'm gonna get 11mpg, I might as well sound like it.

I'll PM you about the carb.

Originally Posted by madscience

Yeah....can't wait on my exhaust. I figure if I'm gonna get 11mpg, I might as well sound like it.

I'll PM you about the carb.

Actually my MPG never really went down all that much, but I also have the 2.75 rear which gives me really good crusing MPG. I get better economy with my '68 than I do my 2003 Dodge Ram 1500 with 5 speed.

But I do expect that to change with a 4bbl.

somthing that i did on my 352 that was a nice drivability mod was to get a duraspark unit i got mine from a 74 f100 at the junkyard i took the dizzy the box and the harness only 3 wires to hook up and they all go to the solenoid (points work well but imo they are a pain)

Originally Posted by meteor545

(points work well but imo they are a pain)

Do people really have that much trouble with points??? I haven't even looked at mine in 2 yrs at least.
The only thing I've noticed in that time is I need to either change or clean my plugs as I notice a little bit of a miss recently. When ever I get around to doing that I'll see if I need to change the points or just clean them a little bit also.

Deb