Some interesting reading for sure ported intake

Thanks- that answers that.

You can push a low deck block a lot further than a tall deck. Most say 650 hp is about it with an rb, 800+ with a low deck. On top of that there is some weight savings, both from the block and rotating assembly. I don't know how well the low deck 6 pak flows, so that needs to be looked at.

The Indy EZ's will raise the intake slightly higher than the stock heads due to their design. The Shaker still works on my '70 E-Body though. It is snug though.

Those old sixpack intakes surprise a lot of people with how well they can be made to work. The 493" motor I was running dynoed at 684hp below 5500 RPM. There's a write up on it on Hughes website. It's all about the combination. That was with a hydraulic roller. I dropped the compression 2 points and am converting to a slightly larger solid roller cam. The motor won't get on an engine dyno, but I'll eventually run it on a chassis dyno one of these days.

I've since learned that even ported sixpack intakes do significantly hinder the flow of my ported Indy EZ's, which flow around 345cfm at .600 lift. I had Hughes port my intake to the limit of their current knowledge, but they are digging deeper into them to find more flow as of this writing. This could get interesting real soon.

I'm going to installing a set of 3 modified 2300 series mechanical secondary carbs (the old Direct Connection Mechanical secondary Race carbs) that flow more than they did stock. Just how much more I won't know for a few weeks. The center 350cfm carb is being replaced with a 500CFM outboard mechanical carb, which didn't have idle circuits in them stock. This is being addressed so it can be used as a center carb. The boosters and barrels are being removed and the carbs are being converted to aerosol booster style by C&S Specialties. They build a lot of race two barrels for the roundy round guys.

Thanks John- nice car car you have there!
I'd be curious to see how the car responds with those different carbs and the solid roller.

The six pack engine in my GTX is 708 horse on pump gas. I used a 73 block, installed cross bolted main caps, put bushings in the lifter bores, bored .030 over, 4.5 lightened stroker crank and assembly from 440 source. Solid comp roller cam, 633 lift I think, 1.6 crane rockers, ported Edelbrock RPM heads. Head flow 327 on the intake side. Port matched the intake, installed 1/2 spacers on top of the intake. Do not mess around with the top side of the manifold. Leave it as cast. Now I sent my carbs out to Gary Williams and had him work them over. I wasn't happy with the throttle response so I got a set of mechanical carbs. Sent then out, very happy. Now the stock air cleaner with a paper filter will cost you 40 horse. A K&N filter robs 22 horse. My 535 is all done by 6000 rpm. When we dynod my engine, we tried 7 different manifolds. A single 4 barrel ported made 15 horse more. A tunnel ram made the same, just pulled more rpm's. Tried a crossram, that castrated the engine.

When you say you went to mechanical carbs are you talking about the ones that have accelerator pumps on the secondaries or just straight mechanical linkage?
Thats quite a power loss from the air filters- more then I would have initially guessed. Maybe I shouldn't be surprised the element doesn't look very tall so maybe not a lot of area to it overall...

I've got a 4 speed backing up my 535, a dana with 4:10. I run 275/60 R15 tires. At 60mph I get 11 mpg. If I go 65 mph, I get a whooping 4 mph, lol. Great combination. Have to run a duel disc clutch.

Sounds like a great car Copchaser

I've tested a single 6 pack Fram paper air cleaner versus two of them stack on top of each other together and then a single K&N and then two K&N and finally a six pack air cleaner base with no air cleaner and it made 5 HP more with no air cleaners, 7 HP more with two paper elements compared to one, same results with the K&N elements
My motor was much smaller, 511 C.I. with a 4.250 stroke and 4.375 bore with 9.25 to 1 comp ratio, it made the best HP, 612, at 5500 RPM and the best torque of 644 Ft. lbs. at 4500 RPM.
I flogged the heck out of that motor testing three different sets of carbs., ignition timing, valve lash and air cleaners that day
Once the motor was broken in and leveled out I saw 12 HP gain from worst to best parts tests

The carbs I'm running are the old direct connection mechanical carbs, the ones with a accelerator pump on each carb. The GTX runs in the lower 10's. Stop by, I'll take you for a ride.

What's the general consensus on max cubic inches vs horsepower for a stock six pack intake and carbs? How about with the DC aftermarket carbs?I know cylinder heads will be a variable here.
RT

Why would I want to go slower, my pump gas 3450 Lb. duster ran high nines at 134.6 MPH with the full exhaust and air cleaner on
My current bracket car runs 9.0 at 147.+ MPH Quicker and faster this year, hopefully
BTW, my old six pak motor did make the most HP and torque with a set of the mechanical carbs. jetted stock The stock 1971 replacement 440 carbs made 7 HP less

Hey glad i found this post
Stock appearing motor right ?
Lol .
I think i recently posted one like this ..
there was lots of feedback
But only 5-6 hund horse

It's not a requirement by any means but if there is things I can hide or disguise I will be trying. The size of shaker scoop will certainly help me out There. This isn't nessesarily a stock appearing deal so my only big limitations are the block and induction choices to fit under the shaker. My power number isn't carved in stone either, it's just to where I think I'll be happy with its performance, anything less it would be a under-achiever. My last pump gas street driven small block made 1.59 hp/cube and was "good enough" I expect no less from thing and it will likely have another 60 cubes minimum on my small block.

You'll be better off with a low deck for fitting something under the shaker. My origional a12 base didn't really fit under the hood on the rb with raised port sr heads. Works great on the 400 block though.

There certainly appears to be some advantages going that route- and that one right there is a biggie.

All the 400 blocks have way better main webbing than any of the 440 blocks, build it big C.I. wise

Ok, how about this thought. With 440-1 heads the exhaust port is raised but the low deck is "shorter" we'll say- do you think there is a chance of using a regular header with that combo. If I didn't have to buy headers that's money that can be spent elsewhere.

Nice. What kind of mph?