Hi, recently got an 82 with a 4-speed. Swapping out the stock 350 for the following:

Freshly mahined 400 SB w/ 2-bolt mains
Brodix 210cc Heads (1028100)
SCAT Rotating Assemby (1-41255BI)
Edlebrock High Rise Dual Quad Manifold (came with the car)
Holley Headers + Sidepipes (woo!)
Direct Flow or Glasspack slip-ins, unsure still

Street/strip. This setup uses flat tops and 76cc combustion chambers. Block is decked to 0.016" (in case more meat needs to be leveled in the future) with a 0.021" gasket to reach a decent quench. CR estimted @ 10.25 ~ 10.3 which should run just fine on some 93. I don't see the need to go any higher than 210 honestly. I plan on sticking with these Brodix heads as ARF's heads have raised ports. Not to mention Brodix has the nicest staight plug style heads with the right CC size. Anything below 74cc's would put me near the 11:1 ratio, no thanks. Dual quad manifold is also firm, yes I am willing to sacrifice a bit of hp for the oohs and ahhs.

The questions:

#1) What cam should I be running with this setup? Must be a hyd roller! Saw a nice 236/242 but that seems a tad too mild. Take into consideration LSA and cam retardation/advancement (I would prefer to do neither). I read an article somewhere saying that if you have to retard or advance the cam, then you're using the wrong one.

#2) What carbs to use (in terms of cfm)? I personally like Holleys as you can really play with them. But I looked around and couldn't find a Holley "matched set," and Edelbrock matched carbs don't have anything under 500cfm. 1000cfm total doesn't seem friendly with respect to my setup. Is there a way to swap out the jets maybe? Either way I am completely lost on this area.

The cam, heads, and carbs must be done as a combo. In this case, we shall use the heads as the starting point. This setup should push out over 520 hp & tq even WITH a 4x2. If you see a reason for me to go with more/less intake through the heads, please explain why and give your suggested combo to go with it. Thank you all for your input.

 

In order to get the best answer possible it would help if you list your rear end ratio, which 4 speed (1st gear ratio makes a difference), tire height, and how much street vs. strip use you plan. The fact that you'll be using dual quads leaves me out in terms of giving advice but I'm sure somebody will step up to help. Good luck and welcome to the forum.

 

Thanks. And I know for sure it's a muncie, but I wouldn't know whether or not it was modified. I seriously doubt it. As for the tires, I couldn't tell, because the tries + wheels are going to be the last things I do. Also, a LOT more streeting than stripping.

 

I would keep a hydraulic roller in the 236 to 242 @ .050 range and a 110 to 112 LSA for what you see to want. Maybe use 1.6 rockers on the intake for a little more lift.

The 500 cfm Edelbrock carbs will not be too big. Make sure you use progressive linkage and you know the secondaries on an Edelbrock (AFB) has an upper butterfly that responds to engine demand. You don't get a 1000 cfm all at once. You will spend 99% of the time on the rear carb's primary butterflies. Holley's won't fit unless you mount them sideways. A real pain.

 

consult 2or3 can company's and get thiere opinions and compare the specs they give you. advancing or retarding a came is a tuning aid and does not necessarily. indicate the wrong can. who makes this stuff up?

 

Sounds like a nice rig. How are you computing your CR with the 76cc heads? What pistons?

If it were me, I'd lose the two-carb intake and go with a Vic-Jr or RPM dual plane intake. Then set a 800 DP Holley on top. I think she'd perform better, be much more driveable, and you'd spend 1/4 the time tuning it vs. the dual carbs.

You'll like those heads. I'm of the opinion that 210cc or 215 is just right for a hot SB 406. With these heads you can go a bit milder on the cam and still buzz her 6500 RPM.

Bigger heads and smaller cam works great! Misery is smallish heads and biggish cam.

FWIW

 

Yes but without 4x2s this setup wouldn't look as cool I went through a lot of research and blueprinting data to zero in those heads, that's why I'm so firm on them. Pistons are flat tops +6cc, calculated by hand and reconfirmed with several online cr calculators. Oh, and I used my time to hunt down this sucker:

http://www.summitracing.com/parts/CCA-CL12-443-8/

Figured why not hit two birds with the same stone and grab the lifters too, saved about $50. As for the carbs, I thought these would work perfectly:

http://www.summitracing.com/parts/HLY-0-9776/

But someone pointed out earlier that these had to be mounted sideways? Haven't run into that issue, I never knew Holleys were like that :/ Oh, and when i say "dual quad" and "4x2" I mean it as a tunnel ram. A hole will be cut in the hood for the scoop.

 

You are going to run a tunnel ram on the street? No way are you going to get this to perform on the street with good manners. Tunnel rams may look racy but I'll tell you anyone with a proper setup single 4 barrel will make more useable HP on the street than you will ever think of with a tunnel ram. You can make it work but you will spend more time trying to tune this than you will driving it.

 

When I originally bought this from the owner, he had the stock 350 with the tunnel ram AND running two Eldelbrock 500cfms for a total of 1000cfm. The motor ran perfect. I wanted to bump it down a bit to maximize efficientcy. Is it really that difficult to tune by the way? Thats why I asked about possibly swapping jets.

 

I thought you were talking about a lo-rise 2x4 setup also...but a tunnel ram can work...it just takes a little time.

I'd use Holley's. They will fit end to end on a tunnel ram if they are 4160 style. Or you can mount sideways with proper linkage and REALLY look cool without much issue. Actually that linkage works very smoothly.

Do a seach on Car Craft. They did an article on playing with a tunnel ram on a street motor and getting it tuned that was pretty good.

Plan on a lot of initial timing to help. What gears, converter (if auto) or trans do you have?

A 236/242 hyd roller is fairly stout. 11.0 isn't out of the question if you can get 93 octane. I build a lot of motors with that and more with no issues on pump gas. We just did a 400" with Dart 200's that made 555Hp with out of the box parts...nothing fancy or ported. Did use a solid roller though...but nothing crazy.

I don't think the small block AFR head exhaust ports on the *normal* heads are raised are they? Big blocks yes...but still no big deal usually. But I like Brodix also. Any CNC option you spend $$ on is a good thing.

JIM

 

I'm running a 406 tunnel ram setup for street use on my '81 automatic and it runs great. Not had a problem yet. This is my first winter with her however and I have noticed you have to let her run for a minute or so before she'll idle on her own...guess the tunnel ram is warming up. Other than that, no issues. I'm running dual 4160 450 CFM Holleys with vacuum secondaries, balance tube, no choke, and solid linkage. 3.55 rear gears, 295/50R15 back tires, Headman Shorty Headers with straight 2.5" dual exhaust thru 1 chamber flowmasters and a H-pipe. I have a mild cam (270 total duration, 110 LSA, .510 lift) and 1.6 rockers. My next upgrade will be to those same Brodix 210cc heads (I have 186 iron "fuelie" heads at the moment and they're only pushing about 160cc). Good luck with your mod.

Jeff

 

Ha! Wow! That is outstanding! I am planning on the exact same setup but with a Weiand 7223 scoop. I guess my setup with the cam and carbs I posted will work just fine then. The only reason I went with a slightly more aggressive cam is because I have a manual trans, so why the hell not

 

I had a big tunnel ram on a street rod. Dual Holley 650 center squirters for drag race days and dual 500's for street driving.

Like I tell everybody. Super chargers and tunnel rams do not like overlap reversion. So you want high lift, 114 or even 115 or 116 LC and the least amount of duration for the rpm desired.

Big lobe sollid rollers create the highest vacuum. You really want to run over .620 lift. I would not run a mild H-roller, but it could be done.

What is the listed rpm range on your intake.