Just got around to getting on the computer..been deer hunting and I am old school and do not have a cell phone.
Tall tunnel-rams are the way to go for added power over many single 4 barrel intakes.
Big Joe was working at or for edelbrock when they came out with the single 4 barrel tunnel-ram and he said it had the worst distribution of any intake ever tested and made 100 hp less than the dual 4 tunnel-ram.
I always went tall on the rams 10" or more.
I ran AFB or Edelbrock carbs and always will on my tunnel-rams.
Tried the 450's in the Holley brand and the thing was terrible and finicky out of the hole, once you got it wound up and it cleaned up it pulled ok but not near as much pull as the dual 1405 edelbrock 600's this was a 355" with 280H cam on a 106 LSA [email protected]
.050 and ported 993 heads.
I ran another dual 4 on a 350" with a 280H on a 110 LSA and same carbs.. picked up power everywhere VS my performer RPM intake which I tested with 3 different carbs.
Qjet and a 750 Edelbrock 1407 and a very much modified and epoxied 4779 Holley that flows.
I do not like the Holley carbs myself as my experience with them is long and you really need to tweak some things to really dial them in and I found for smallish or meduim size cams in the 350-427" engine size the little 1405's work excellent out of the box.
Of course set float levels correctly right off the bat.
smallish cams like 268H [email protected]
.050 for those not in the know to the meduim sized cams like the 292h [email protected]
Throttle response is stupid fast with a tall tunnelram and 2 of those carbs.
.060 over 396" BBC i built for a buddy 280H on a 108LSA 11:1 compression 210 psi cranking pressure strip dominator and 800 carb vs the tall ram with 2 1405's.
The 1405's on the ram had my buddies hands shaking after he got back from a test drive.. said it was ridiculous fast.
second gear from a roll and he tickled the throttle , blew the tires off and the shift light came on 7000 rpm before he knew what happened.
He said he was absolutely not ready for that.
that is in a 1966 chevy truck 4200lbs with driver and 3.08 gear.
That summit ram looks like junk. NO WAY the inner and outer runners will run even remotely close to each other.
If you fab a single 4 ram you need it tall and join all the runners like you see in a Dart single plane intake.
Long gradual runners that enter the cylinder head at the same angles.
Here is my 57 with a ram at the track beating up on my buddies 550wheel HP supercharged 2015 mustang.
I have 601 heads 1.84-1.50 valves Ported of course and a 280H cam 110 LSA cheap single point distributor that was not locked down tight and this pass was with 28 total timing.Yea distributor moved when i did my burnout. lost 10 degrees of timing.Ouch. still won the race though.
My buddies nova I built for him, with one of my old TR1YX 12" tall rams and some specs.
1978 Chevrolet Nova 2dr 1/4 mile Drag Racing timeslip specs 0-60 - DragTimes.com
If you go tunnel-ram go tall and dual 4's The Edelbrocks are stupid easy and you can have jetting all over the place with a tall ram and not hardly notice any difference.
I will say this though..I like to add an ink pen spring to the orange step up springs to get the power circuit to come in much quicker than you can with available stock springs from Edelbrock.
Notice I said From Edelbrock.. as many of the Stock Carter AFB original springs from the 1960's carbs were stiffer.
Abel racing has been on TV and my buddy Andrei owns it I tested an RPM intake and the same day I went home and installed my dual 4 RAM and went back and put the truck back on the rollers and made 53 more HP everywhere.. he could not believe it and kept asking what else I changed..I said well the single 4 i had an HEI and now I am running a single point distributor. Same timing curve.
Here is my 57 with dual 4 and single point autozone distributor point bounce at 7150-7200 rpm.
280H and small valve 601 heads 350".
I drive my stuff like that all the time. No loss of low end there and I have never seen loss of low end with a tall one.