new intake, cam, and carb?

[67gt]

I want to upgrade the intake cam and carb on my 390 . The performer looks better on paper (with the stock heads and carb) for me then the performer rpm. I drive around 1,500rpm (3,000 on the highway) and shift between 3,000 and 3,500 RPM, the highest it has seen is 4,500. I have heard that the performer rpm is much better so I think I will go with that one. Now I also heard that the Edelbrock recommended cam is too aggressive for low end, is that true? If so what cam would you recommend and should I change the valve springs too? Finally, I was thinking of the Edelbrock 650cfm carb. Is this a good cfm? or should i go with 750? I want to upgrade the heads soon too. I don’t want to be constantly adjusting the carb, however if there is carb that will make a noticeable power increase I will learn how. Right now I have an autolite 4300 and I don’t like it. BTW does anyone know the cfm rating for that carb?


Thank you

 

[5.0ina66]

I'd go for a PerformerRPM intake, and maybe the 750cfm carb. Those will both make great power, and give you room to grow. As for the Edelbrock cams, there are better ones out there, and from the 390 cars I've seen locally, the RPM cam is too lumpy for the amount of power it (doesn't) make. I'd go with a Comp XE-series cam, or an FTI custom cam. The 4300 is about 500cfm.
HTH
--Kyle
PS: Build quality is kinda sloppy on the assembled E-brock FE heads. They're also reputed to use cheap azz springs. I'd buy em bare and have a good machiene shop set them up.:Track:

 

[67gt]

thank you for you reply 5.0ina66
I still dont know what I am looking for when it comes to the cam? On summit racing I only saw the XE for a chevy and it was just under $400, too much for me. It seems to be a little overwhelming. The stock lift is .481 intake and .490 exhaust, I don’t know the duration. I want a lot of low end torque good to about 4500-5000. Is that possible?


Thank you

 

[D.Hearne]

Best intake for a 390 is the factory 428 PI unit or the repro unit from Blue Thunder. Either work well with mostly stock motors. The 390 in my 68 Merc (4200lb-2 door Monterey-same as a Galaxie) has the same heads and pistons as the GT 390 and I'm running a Crane 272 degree Energizer cam. This cam has great bottom and mid range combined with a 428PI intake and 750 vacuum sec. Holley. Also doesn't require an adjustable valvetrain. Idles smooth with only a hint of lope when cold.

 

[67gt]

D.Hearne is this the cam, http://store.summitracing.com/partd...utoview=sku&part=CRN-134052&Ntk=KeywordSearch ?
do you recommend upgrading the valve springs too?
Also were can i find the blue thunder intake? The original 428 pi is very expensive.

thank you

 

[5.0ina66]

OK, I like D.Hearne's choice of the Crane PowerMax272 cam, as it's cheaper and a little bigger in the right places as compared to the Comp XEs (which BTW Summit has for $114.95 for an FE, dunno where the $400 came from?). Unfortunatley, with a cam like that and a good intake, you shouldn't have a problem winding it to 6000 RPM IMHO, 4500-5000 RPM isn't a very good goal; besides not being much fun to hot rod around it and probably signing off @ 4800 RPM, it'd be ALL torque and lowend, and no spin. That's for mudrunning and towing; not a big-block hotrod

 

[5.0ina66]

OK...just scared myself when I looked at the price of the blue thunder intake....$510? Jeez....the cheapskate in me says buy an Edelbrock!
HTH
--Kyle

 

[67gt]

I saw 400 for something. oh well
I dont think the rest of the engine will handle 6k the tach only goes to 6k so my guess is that redline is 5,000 or so.

 

[67gt]

Yeah i know... the originals are a lot more.
How much better is it then the edelbrock? Is it worth the extra $215+?
so I should be good with the edelbrock preformer rpm intake and the crane cams energizer 272 cam, and a 750cfm carb?
is there much diffrence between a edelbrock750 and a holley750?
Thanks very much for your help guys. There is not much information my mostly forgotten 390

 

[tylerrocks]

Generally speaking from what I have read, people tend to have more trouble with edelbrocks than holleys.

Tyler

 

[5.0ina66]

Generally speaking from what I have read, people tend to have more trouble with edelbrocks than holleys.

Tyler

One of my buddies dads bought a dual quad setup and dual 600 Holleys for his truck back about '89 or so...cost him $700 IIRC. Within a few months, the Holleys had been thorugh 3 rebuilds and pissed fuel all over the nice new intake. Hacked up a buttload of $$$ and replaced them with Edelbrocks...no problems in the 2 years before he sold it. :Teh-Win:

 

[67gt]

thats good to hear because the edelbrocks are another $200 less hahaha. I like to save money.

with this set up can I expect worse gas mileage or will it be about the same. I get 9 or so mpg cruising around. And 6 or 7 when I have more fun.
and an estimate of HP and TQ gains

 

[tylerrocks]

Agian I used the terms "generaly speaking" and "from what I have read", Take it as you will.

Tyler

 

[D.Hearne]

One of my buddies dads bought a dual quad setup and dual 600 Holleys for his truck back about '89 or so...cost him $700 IIRC. Within a few months, the Holleys had been thorugh 3 rebuilds and pissed fuel all over the nice new intake. Hacked up a buttload of $$$ and replaced them with Edelbrocks...no problems in the 2 years before he sold it. :Teh-Win:

If those Holley's went thru 3 rebuilds, then your buddy obviously didn't know what he was doing to start with or the carbs were old and worn out. I'm running a set of repro Holley 250 cfm 2 bbls ( that's THREE carbs on the same intake) on my 331 in my 89 Ranger. Since setting them up for the motor ( getting them jetted and idle set) I have not touched them ONE time in over a year. After the truck sat most of the summer ( no A/C) I'm now driving it daily, round trip 55 miles to work. NO overdrive and it gets 16 mpg Once a Holley is set, if you want to keep it set, THEN LEAVE IT BE :Zip2: As for you're being scared off by the cost of a Blue Thunder or original Ford intake, that's the cost of perfection. I've heard stories of some that had fitment issues with Edelbrock's intakes, that ain't gonna happen with an original, unless someone's milled it. The one I have on my Merc came off a police 428 and had some corrosion in the exhaust cross over passage. Paid $200 for it and cut out the corrosion and welded the ports shut. Didn't need the extra heat anyway. ----------- The Crane Energizer can be run with stock springs, but if they're old, I'd replace them. ( that can be done with the heads on the motor, after you break in the cam, with the right tools)

 

[D.Hearne]

Generally speaking from what I have read, people tend to have more trouble with edelbrocks than holleys.

Tyler

Yea, people that are OK with mediocre performance, and are unwilling to learn how a carb functions and tune it, love Edelbrock/Carter carbs ONCE A CARB IS SET & TUNED PROPERLY, it should be left alone. Only in rare cases will one become out of tune with the rest of the motor, and this is usually the motor being out of tune, not the carb's fault.

 

[D.Hearne]

I saw 400 for something. oh well
I dont think the rest of the engine will handle 6k the tach only goes to 6k so my guess is that redline is 5,000 or so.

ANY 390 will handle 6000-6500 rpms. They've got excellant rods with 3/8th bolts and the stock cast iron cranks are generally bullit proof. A little prep work to a cast 390 crank and it's good to 7500. If your gas mileage is that bad in a big block Stang, then someone's swapped the rear gears or it's really out of tune. Driven sensibly on the freeway, it ought to knock down mid teens in fuel mileage if the rear gears aren't too steep.You've got a fairly light car with boat loads of torque and that should get you decent mileage if you keep your foot out of the carb.

 

[65up2d8]

Where have you been lately D. Hearne? Your post count has greatly diminished recently. With you and Historic on hiatus quite often of late, the evil forces are at work spreading misinformation about FE's and suspension handling tips! :Word:
Seriously, I was hoping you'd opine on this subject as you appear to be the resident FE guru.

 

[D.Hearne]

Where have you been lately D. Hearne? Your post count has greatly diminished recently. With you and Historic on hiatus quite often of late, the evil forces are at work spreading misinformation about FE's and suspension handling tips! :Word:
Seriously, I was hoping you'd opine on this subject as you appear to be the resident FE guru.

I haul fuel for a living now and since Katrina blew thru here, we've been working 12+ hours a day, 6 days on (when we're lucky)1 day off. I commute 55 miles back and forth to work, so that doesn't leave much free time to spend here. On the bright side, all the extra money I'm making is being stashed away for the down payment for the new 06 Stang ( if it ever gets here ) That's gonna knock the notes down big time. Latest word from Ford is, it's scheduled to be built next week and delivered by about November 18th.

 

[67gt]

will these valve springs wook well http://store.summitracing.com/defau...t=CRN-99839-16&autoview=sku&Ntk=KeywordSearch ?

And what are your opinions on this carb http://store.summitracing.com/defau...earchinresults=false&N=0&target=egnsearch.asp

Thank you

 

[D.Hearne]

will these valve springs wook well http://store.summitracing.com/defau...t=CRN-99839-16&autoview=sku&Ntk=KeywordSearch ?

And what are your opinions on this carb http://store.summitracing.com/defau...earchinresults=false&N=0&target=egnsearch.asp

Thank you

Same carb I've got on my 68 Merc's 390. Works perfectly only needed a lighter secondary spring ( purple) to let the secondaries open sooner. Not sure what springs those are (ain't got time to research right now) but being double springs, they sound a tad heavy. Use what ever springs Crane recommends. The GT/CJ spec stock springs will work well with the 272 degree Energizer, these are single with a flat wound damper.