Engine builders? Best intake choice for steady 4000rpm cruising?

[cop car wagon]

No, I'm not putting overdrive in.
3200lbs, 3.23 4spd. 25.5in tire.
85 mph = 3600
90mph right near 4000.
Got to keep up with traffic. 100-150 mile trip common, but also with 1000 mile per day potential.

My new "stock" 340 motor has molnar rods, 550gr pistons, minor headwork X heads, 310° 530" 107 solid cam, 3310-780 holley, tti headers.
When not crusing, will see blips to 6500.
Manifold selection include street dominator ( current) TM5, (past favorite),rpm air gap, and strip dominator.
I'm past torque curve of dual plane, but will the ram effect of the big single plane help?
Previous 4500 mile trip with current 340, 284°484" hydraulic netted 14.5mpg.
Followed up with a 4000 mile trip with swapped in 2.76 gears, and mileage fell to 12. Cruise rpm fell below cam curve.
So all you bench race experts!! What intake? Bonus points for a hp guess.
My engine builder was not impressed enough to offer a hp guess, or suggest a dyno run. Too mundane compared to all the roller cam stroker builds.

 

[go-fish]

@cop car wagon
Not an engine builder but curious because I am planning some changes to my combo (340/4sd/3.21 SG/27" tire/224@.050 & .468") and I have cross country aspirations as well. What do you run for the valvetrain and what is your 1st gear ratio?

 

[cop car wagon]

Current valvetrain is bushed 273 rockers, spot faced for adjusters, 40,000 miles running at 3500 and more.
Because its a street car and we have hills everywhere I run a 3.09 gearset with 1-1 4th in my 833.
I like my clutch, and am not drag racing.

 

[junkyardhero]

airgap

 

[33IMP]

I would probably stick with the street dominator.
Strip dominator probably would make more power at 4000 up, but for a street driven stick car with a relatively mild gear, I think it might give up too much bottom end torque.

 

[RustyRatRod]

Airgap all week and twice on Sunday.

 

[crackedback]

Air gap or street Dom

 

[cop car wagon]

Its more of a highway driver. I hate traffic.
Its looking like I might have a spare Strip Dominator.
Like new.

 

[junkyardhero]

Dyno-Testing Small-Block Intakes - Induction Extravaganza - Mopar Muscle Magazine

Tune in as we do a comparison dyno-testing on small block intakes from The Edelbrock Torker II to the Holley Strip Dominator. More details, reviews and photos, check out Mopar Muscle Magazine

www.hotrod.com

 

[go-fish]

@cop car wagon Your 3.09 A833 + 3.23 overall 1st gear ratio is 9.98:1 and your healthy cam would like a single plane, no? Seems like the low speed cruising department is taken care of quite nicely. That is part of the changes I was referring to in my reply, changing my transmission ratio. Also, swapping the 8.25 for an 8.75 but only going from 3.21 to 3.23 rear gear. I also have 273 valvetrain and running SFT. Manifold is an LD340.
Again, I'm no expert but I would try a taller tire and see how that changes your current set up's cruise RPM. Sorry, don't want to get off the intake manifold debate here.

 

[TT5.9mag]

At 4000 rpm cruising you are not past the effectiveness of the rpm air gap. In fact it donkey stomps just about every other intake right there. Use the rpm air gap.

 

[RustyRatRod]

At 4000 rpm cruising you are not past the effectiveness of the rpm air gap. In fact it donkey stomps just about every other intake right there. Use the rpm air gap.

Not to mention "PLUS" it will kick *** in the lower ranges as well. The single planes might drop off in comparison.

 

[TT5.9mag]

With that cam and mildly worked x heads, (depending on compression ratio) I’d say you’re 360-380 hp.

 

[cop car wagon]

@cop car wagon Your 3.09 A833 + 3.23 overall 1st gear ratio is 9.98:1 and your healthy cam would like a single plane, no? Seems like the low speed cruising department is taken care of quite nicely. That is part of the changes I was referring to in my reply, changing my transmission ratio. Also, swapping the 8.25 for an 8.75 but only going from 3.21 to 3.23 rear gear. I also have 273 valvetrain and running SFT. Manifold is an LD340.
Again, I'm no expert but I would try a taller tire and see how that changes your current set up's cruise RPM. Sorry, don't want to get off the intake manifold debate here.

In theory, yes a larger tire could drop 1-200 rpm. Car is set up for handling, and running 245/60/15 on15x8 all round.
Running the mountians require good grip, of course I might switch to 17" for better tire selection.

 

[RustyRatRod]

In theory, yes a larger tire could drop 1-200 rpm. Car is set up for handling, and running 245/60/15 on15x8 all round.
Running the moutians require good grip, of course I might switch to 17" for better tire selection.

Drive that beeotch. It sounds like fun.

 

[cop car wagon]

With that cam and mildly worked x heads, (depending on compression ratio) I’d say your 360-380 hp.

I forgot to mention. 10.25

 

[go-fish]

15x8 all round.

Heck Yeah! Pics?

 

[TT5.9mag]

I forgot to mention. 10.25

I think my guess is accurate

 

[cop car wagon]

I was only hoping for 350+.
I was building for roll on power at cruise rpm, bigish carb, small throttle opening.

 

[TT5.9mag]

I was only hoping for 350+.
I was building for roll on power at cruise rpm, bigish carb, small throttle opening.

I think you’re above that if it’s a measured 10:25 comp and ported x heads. Do you have a cam card?

 

[cop car wagon]

Not handy.
No one has any comments on the TM5.
My fav from the old days. Great at top end, and never any loss at low end, but that was on a stock motor.

 

[TT5.9mag]

Not handy.
No one has any comments on the TM5.
My fav from the old days. Great at top end, and never any loss at low end, but that was on a stock motor.

Boat anchor. Sorry

 

[Oldmanmopar]

I always liked the Strip Dominator at those RPM's. With big exhaust primaries easy in easy out.