Which intake for my truck???

[Olive1970]

Considering the Edelbrock 2101 or 7104?

http://www.summitracing.com/parts/ed...make/chevrolet

http://www.summitracing.com/parts/ed...make/chevrolet

Not sure which one to get, don't want to get too much intake for the engine or too little either. A little about my setup: Chevy 357 4 bolt, eagle rods, SP coated flat-top pistons, 1.94/1.60 heads, upgraded springs. .488/.510" lift cam, MSD HEI ignition, Holley Spreadbore carb (650 cfm), Headman headers, 3" exhaust with hedman x-pipe and flo-pro muffs.

Thanks for all your help! I have had so much trouble with this truck lately im about ready to throw in the towel

[Roninwolf]

The RPM will match your cam profile better.

[SS Tim]

Are you still planning on running 3.07 gears? That is what a 350/th350 70 C10 had as stock.

[INSIDIOUS '86]

First off ditch the Holley spreadbore the whole lot of those should have never been made. Those things are a nightmare

Second. What's your cams duration?
A performer rpm intake seems like the better match so far
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[Olive1970]

Originally Posted by SS Tim

Are you still planning on running 3.07 gears? That is what a 350/th350 70 C10 had as stock.

I am still planning on running them for the time being, if I ever change them.

[Olive1970]

Originally Posted by INSIDIOUS '86

First off ditch the Holley spreadbore the whole lot of those should have never been made. Those things are a nightmare

Second. What's your cams duration?
A performer rpm intake seems like the better match so far
Posted via Mobile Device

Are the Holley Spreadbores really that bad? It seems like it runs the best on the truck so far, well for the most part. I also have a Street Avenger 670.

The duration at .050" is 234 244 on the cam.

[wesmigletz]

I've had decent luck with the old spread bore double pumpers. The 7104 is a nice intake, too. However, I think your truck will run better/quicker with a sum-1103 or sum-1105 cam, given your converter and gearing.

[cdowns]

if you r running 307 gears and combined with that oversized 3" exhaust you r loosin alot of bottomend torque

[Olive1970]

Originally Posted by cdowns

if you r running 307 gears and combined with that oversized 3" exhaust you r loosin alot of bottomend torque

FYI, I did have 2.5" exhaust on this truck before and it restricted the engine considerably. I have done my homework before putting the 3" exhaust on.

[WIDESIDE72]

Originally Posted by Olive1970

FYI, I did have 2.5" exhaust on this truck before and it restricted the engine considerably. I have done my homework before putting the 3" exhaust on.

I would suggest the RPM as well.

My experience has been that 2.5" duals are plenty. I would also suggest a lower rear axle ratio if tou want to realize the full potential.
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[TBONE1964]

Gary,

You are asking the right question to the wrong people (no offense to anyone).

Contact the tech department of your cam manufacture and they will ask you some simple questions and recommend an intake that will work best for your combination of parts.

That is what these people do day in and day out. It is easy to say that your exhaust is wrong, your gear is wrong, your converter is wrong, your truck is to heavy, etc... I would love to be able to say to you, "Gary if you use this intake, this is exactly what will happen" but I would only be guessing with your money.

[Fldawg]

from what you have told us, i would go with the first intake, you want it to work off idle and i doubt your gonna run over 5500 rpm

[CC69Rat]

I'd do the RPM air gap. Your engine sounds like it flows really well for a street engine.

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[WadmalawJoe]

Originally Posted by CC69Rat

I'd do the RPM air gap. Your engine sounds like it flows really well for a street engine.

Posted via Mobile Device

X2
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[hayhauler71]

Originally Posted by WadmalawJoe

X2
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x3

[INSIDIOUS '86]

Originally Posted by Olive1970

Are the Holley Spreadbores really that bad? It seems like it runs the best on the truck so far, well for the most part. I also have a Street Avenger 670.

The duration at .050" is 234 244 on the cam.

That's a fairly healthy cam. Your intake valves are a little small for that the air gap is a good choice or the wieand equivalent which I a little cheaper and has some more low end and very close to the same top end. What's the compression? Some 2.02 fuelie heads will bring some more out on that engine.
As for the spreadbore they work but they were designed as a quadrant replacement and the over size secondary's make for an unstable fuel curve at the top end. Depending on what rpm your turning that engine normally a normal double pumper or vac secondary will give it a good all around feel. The plus side is the spread bore will give a better cylinder fill and response at low rpm

Right now I would lean towards the wieand
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[CC69Rat]

Isn't that one the team G or something like that? Absolutely the Wieand would be great too.

If you go with Edelbrock make sure you get their gaskets and the 'gask-a-sinch' product they sell. Your intake will seal a lot better and not leak oil around the 3/5 and 2/4 ports.
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[Olive1970]

Originally Posted by INSIDIOUS '86

That's a fairly healthy cam. Your intake valves are a little small for that the air gap is a good choice or the wieand equivalent which I a little cheaper and has some more low end and very close to the same top end. What's the compression? Some 2.02 fuelie heads will bring some more out on that engine.
As for the spreadbore they work but they were designed as a quadrant replacement and the over size secondary's make for an unstable fuel curve at the top end. Depending on what rpm your turning that engine normally a normal double pumper or vac secondary will give it a good all around feel. The plus side is the spread bore will give a better cylinder fill and response at low rpm

Right now I would lean towards the wieand
Posted via Mobile Device

I am not 100% sure on what the compression value is. I have known for awhile that the heads are the shortcoming on this engine, I was going off of what the engine builder suggested but those suggestions have not always worked out. I wish that I could get new heads but it is simply not in the budget for me.

I have an old weiand on there now, but it is leaking (sucking air) so that is part of the reason for replacing it. As far as rpms, I am turning up to 6k with the hammer down. My biggest issue has been a stumble or hesitation when accelerating from a roll, I didnt have it as much with the spreadbore carb as with the street avenger. Granted, I found out the intake was leaking when I pulled the spreadbore off so that has made matters worse. Just not sure which carb I should use either?

[Olive1970]

Originally Posted by CC69Rat

I'd do the RPM air gap. Your engine sounds like it flows really well for a street engine.

Posted via Mobile Device

I looked at that one also as a possibility. My biggest concern was "outflowing" my current cyl heads?

[Olive1970]

Originally Posted by TBONE1964

Gary,

You are asking the right question to the wrong people (no offense to anyone).

Contact the tech department of your cam manufacture and they will ask you some simple questions and recommend an intake that will work best for your combination of parts.

That is what these people do day in and day out. It is easy to say that your exhaust is wrong, your gear is wrong, your converter is wrong, your truck is to heavy, etc... I would love to be able to say to you, "Gary if you use this intake, this is exactly what will happen" but I would only be guessing with your money.

That is a great idea, didn't really think of doing that yet. I should give them a call tomorrow, Thanks!

[CC69Rat]

Do you know the casting number on your current cyl heads? .. just the last 3 numbers. Do you have power steering, etc.?

Have you thought about changing over to vortec heads and intake style? Do you know approx compression you have now? 64cc heads would wake that motor up! Dart iron eagle heads might be a middle of the road option for you to get her breathing a little more too.

With gas as expensive as it is and a th350, with a stall I think a 3:07 would do fine. Any more than that you'll blow the tires off ( just my opinion) remember its a truck without a lot of weight back there. I'd save that gearing for the highway / gas mileage.

Change to 700r4.. you'd get that bottom end PLUS the fuel mileage on the highway. (Or a GB od.. same idea)

Just some things to throw out there for you. You have a ton of options. But if you went with the RPM age, you'd have it if you ever changed heads. .. humm.
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[72chevyk10]

yall realize the regular performer rpm, and the rpm airgap is exactly the same performance? just the air gap is harder to drive in colder weather...

a standard performer is not much better then stock. the rpm is the one to go with in most applications imo.. cept stockish rebuilds, but even then the rpm will make a bit more power

[Olive1970]

Originally Posted by CC69Rat

Do you know the casting number on your current cyl heads? .. just the last 3 numbers. Do you have power steering, etc.?

Have you thought about changing over to vortec heads and intake style? Do you know approx compression you have now? 64cc heads would wake that motor up! Dart iron eagle heads might be a middle of the road option for you to get her breathing a little more too.

With gas as expensive as it is and a th350, with a stall I think a 3:07 would do fine. Any more than that you'll blow the tires off ( just my opinion) remember its a truck without a lot of weight back there. I'd save that gearing for the highway / gas mileage.

Change to 700r4.. you'd get that bottom end PLUS the fuel mileage on the highway. (Or a GB od.. same idea)

Just some things to throw out there for you. You have a ton of options. But if you went with the RPM age, you'd have it if you ever changed heads. .. humm.
Posted via Mobile Device

I would have to check and see what the casting number is. I know they are 400 SB heads from around 1974. The truck does have power steering and power brakes. I would guess the compression ration to be about 9.5:1 if not a little higher...

I have thought about changing the heads, as it would be a big improvement. It is a project I just don't have the funds for at this time or wanting to get into quite yet.

These are all great suggestions, really appreciate your help and everyone else too!

[Olive1970]

So would it be better to run the Holley Street Avenger 670 over the Spreadbore 650? I have both. Either way I will have to run a spacer on the carb because of the location of the booster port on a Edelbrock Performer RPM intake.