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Re: 496 Street low Deck Head Choices? advice needed [Re: 68 HEMI GTS] #2419021
12/15/17 03:00 PM
12/15/17 03:00 PM
Joined: Jan 2003
Posts: 9,866
Weddington, N.C.
Streetwize Offline
master
Streetwize  Offline
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Joined: Jan 2003
Posts: 9,866
Weddington, N.C.
68 Hemi GTS....What size cam you running? Also the SR has the same Raised port intake (better short side) than a standard 906. That's no doubt a great combination in a low deck 511.

Again, nothing wrong with the TF 240 906 port heads, probably an ideal big torque 500" head...Just saying there might be something 'less ideal' (IMO) when you (have to by the given combo choices) combine it with only a 236@.050 Intake lobe hydraulic cam and a 4.25" stroke at ~10.5:1. Something like a single pattern 246@050 with that combo would I think work a lot better, especially above 4500rpm...and it would not lose any appreciable torque down low. I'm assuming that's a 6.535" rod combo? All the more reason the big -1's wouldn't have any problem at all making wheaties downstairs with that small-ish cam in an either/or situation.

Last edited by Streetwize; 12/15/17 03:02 PM.

WIZE

World's Quickest Diahatsu Rocky (??) 414" Stroker Small block Mopar Powered. 10.84 @ 123...and gettin' quicker!

https://www.youtube.com/watch?v=-mWzLma3YGI

In Car:

https://www.youtube.com/watch?v=PjXcf95e6v0
Re: 496 Street low Deck Head Choices? advice needed [Re: Streetwize] #2419074
12/15/17 04:20 PM
12/15/17 04:20 PM
Joined: May 2009
Posts: 511
Temperance, MI
6
68 HEMI GTS Offline
mopar
68 HEMI GTS  Offline
mopar
6

Joined: May 2009
Posts: 511
Temperance, MI
Originally Posted By Streetwize
68 Hemi GTS....What size cam you running? Also the SR has the same Raised port intake (better short side) than a standard 906. That's no doubt a great combination in a low deck 511.

Again, nothing wrong with the TF 240 906 port heads, probably an ideal big torque 500" head...Just saying there might be something 'less ideal' (IMO) when you (have to by the given combo choices) combine it with only a 236@.050 Intake lobe hydraulic cam and a 4.25" stroke at ~10.5:1. Something like a single pattern 246@050 with that combo would I think work a lot better, especially above 4500rpm...and it would not lose any appreciable torque down low. I'm assuming that's a 6.535" rod combo? All the more reason the big -1's wouldn't have any problem at all making wheaties downstairs with that small-ish cam in an either/or situation.


260/266 on a 110. SFT. A touch over .600 lift.


68 Dart GTS "HEMI" 10.30 @ 131 pump gas street car 3780#
69 Roadrunner 511 six pack 10.92 drive to track street car
Re: 496 Street low Deck Head Choices? advice needed [Re: fast68plymouth] #2419212
12/15/17 10:31 PM
12/15/17 10:31 PM
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
B
BradH Offline
Taking time off to work on my car
BradH  Offline
Taking time off to work on my car
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Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
Originally Posted By fast68plymouth
If those are the early style ootb std port victors, and I "had to" pick from that list, those are what I'd use.

Have a little work done to them, run the RPM intake and 1-7/8" headers.

If there were a hood clearance issue, I'd find a nice used low deck Holley SD.

If those are (were) my heads, they were the last set of new-in-box 75cc 77929s I had before changing directions to use the later ones w/ the smaller chambers.

Re: 496 Street low Deck Head Choices? advice needed [Re: BradH] #2419833
12/17/17 01:29 PM
12/17/17 01:29 PM
Joined: Jan 2003
Posts: 9,866
Weddington, N.C.
Streetwize Offline
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Streetwize  Offline
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Joined: Jan 2003
Posts: 9,866
Weddington, N.C.
http://speedtalk.com/forum/download/file.php?id=14303&mode=view

Brad this is a pic you posted on speedtalk and definately helps illustrate my point about the advantage of a raised port when it comes to the short side. Port cross section is only one factor, when you have a big long stroke cylinder with lots of piston speed generated at mid to moderate crank RPM, the larger cross section (IMO at 490+ Ci) is far secondary to port shape / runner volume (yes 40 CC is bigger but it's not THAT BIG, certainly not for a 490+ cube motor (110+ cubes or 1.8Litres bigger than a 383 that a 240TF is not to big for) and maintaining closer to 100% VE above/past the Peak torque RPM. a good bit of that CC volume is naturally because the bigger port is also LONGER, longer runner length is generally good for torque anyway, so that alone is a bit of an "offset", if all else were equal.

Before truly deciding I would like to look at 440Pursuit's -1 Race heads on a flowbench, I still think bigger better port with small street cam is the way I'd go...especially if I have then readily in hand,

Last edited by Streetwize; 12/17/17 01:34 PM.

WIZE

World's Quickest Diahatsu Rocky (??) 414" Stroker Small block Mopar Powered. 10.84 @ 123...and gettin' quicker!

https://www.youtube.com/watch?v=-mWzLma3YGI

In Car:

https://www.youtube.com/watch?v=PjXcf95e6v0
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