[TheGrudge]

Hi all,
First post but I feel I know some of you fairly well due to years of late night southern hemisphere searching...
I could waste cyberspace by telling the story but 20 yrs later my 70 goat is still in pieces. Jobs, girlfriends, bands, more girlfriends, other cars, beautiful children etc etc have protracted what was once a fairly (seemingly hehe) well thought out project.
About 15 years ago (my last rush of blood) left me with this bunch of stuff.....

YC 455
Butler .040 offset ground 4.25/6.8 rod /Ross piston rotating assy.
Butler 270@25" 87cc Edelbrock heads (300 @ 28" ?)
Comp 290b6 solid and related bits
Comp 1.65 rockers
Carb shop stage 3 750 vac sec ( no choke horn etc flow sheet 926cfm)
Th400
3.55:1 safe T track

At the time a Victor was too big, a T2 might have been an option, RPM was a contender, warrior was the koolest intake ever ( this was my dad's car, in the family since about '83 and as a kid I obsessed about obscure Poncho stuff ) but I was never sold on which one. Then came the Northwind. I still don't know. Car is loaded - pwr windows etc and has gotta be 3800#+

If I needed this car as a car it may have moved in the last 20yrs. I wanna roll 'er out, cruise to the track with my daughter and rip out an 11sec pass reliably and regularly.

Which intake? Gearing ok with 28" tyre? (tire)(!)
Trying to make good on a New Year's resolution.
Thanks,
Jordan.

[mechanic17]

As a fellow 1970 GTO owner (since 1988) I sympathize with you. My buddy took his '69 apart with good intentions and it never went back together--meanwhile I've been driving around all these years with people asking me if I'm ever gonna fix it up (it's still in the original paint and dents). Drivetrain is perfect though--it oughta be, it's been rebuilt several times.)

IMHO, you are not seeking an intake, you are seeking a build philosophy. Collecting cool parts while your life goes on is one thing, but when you start a project that big for real, you need a plan.

Big decision: is this a racing toy, or a driver? A 455+ is not likely to need a big cam and even 3.55 gears if you have a TH400 and a modest converter. 12s should be no sweat with those heads, but 11s will require more than a random combo. You will be shifting at maybe 5500, so any of the big intakes will hurt, not help. (I once bought a Victor making that mistake.) So let's say you get an RPM intake and a factory 041 cam with Rhoads--now the car pulls like a freight train and your biggest problem is traction.

Or, if you prefer the high rpms that a big cam mandates, you have a whole different set of obstacles--bigger intake, converter (smaller, actually, for higher stall,) better ignition, exhaust, valvegear. See what I mean?

My advice is to obtain Dyno2003 and Drag 2003 or similar software and do 8 or 10 virtual builds with different strategies. Be realistic, and you will soon have a direction picked out--but I'm pretty sure it will require replacing a few of the parts you already own, no matter what.

Good luck!

[mechanic17]

Oh, if that is the car's original 8.2" rear end, then you will probably destroy it quickly with your engine torque. My car has had several, and only the Ford 9"s have held up.

It's worth a lot of $, so BEFORE you wreck it, you might consider building an 8.5" with new axles, a 12-bolt, or Ford with the exact gearset you want (believe it or not, a 455 can be best paired with a 3.08 gearset or even less if the cam is kept reasonable).

If it is not an original rear end and you don't care about it, then matching the cam to those gears will be cheaper, of course--assuming the rest of the build matches.

[Ron H]

Welcome aboard and glad to hear you are putting your car together.

Your short block, heads and cam have 10 second race potential. But the converter needs to match the combo and be 4200+ stall which is not optimal for street driving. You could get away with a tight converter with around 3800 stall and be in the 11's per your goal stated.

Mechanic makes good points about really determining how much street cruising compared to race you want the build to be.

I don't think you will go wrong with a T - 2 or RPM. Mainly you have to consider the cam for power range and vacuum if running power brakes.

Headers or exhaust manifolds?

28" tire with the 3.55's should work well but it depends on how much highway driving you will be doing and if you are comfortable with over 3000 rpm at 70 mph depending on converter slip.

469 ci with a 87 cc head will give you around 11.25 to 1 cr ratio depending on deck height and head gasket thickness which is on the edge with 93 octane gas and a bit light for the 290B cam.

There are guys running 290B cams on the street but you may want to change the cam depending on the street driving you are doing and other items I pointed out.

[Probird]

I threw together a 440 ci engine with supposedly ported 16 D-ports (didn't really look like much was done to them) and the 290-b6. My car is 5-600 pounds lighter but it ran 6.80 which is pretty close to 10.80's. I ran a victor on it and shifted it at 6000. The convertor stalled about 5000. You should easily get into the 11's with what you have.

[Ron H]

Wow, really good performance from some iron 16 D's!

[TheGrudge]

Thanks guys,
I have two other cars so street use will be the odd half hour cruise to the beach for a burger and to the local track and back (also a half hour drive). Maybe once or twice a month. I have friends with lighter more radical 10sec cars that can do this so I don't think this is an unrealistic idea.

Intake choice was probably always going to come down to T2 or RPM - I'm aware of the pros & cons of each design but wonder which would work best...has anyone run either or both in a similar combo?

I have built and helped build many stout street cars ( mechanic 20yrs ) and can verify that I am aware that no singular part is the answer to building a successful combo, and that plenty of time and research has led to where I'm at with part selection etc. I am however always prepared to accept the opinions/recommendations of those with more knowledge & experience ( I remind my 3 apprentices of this concept regularly ).

3.55:1 is the original rearend. I intend to swap it out for durability reasons anyway - 9" rears came in loads of local cars so are more readily available and affordable than other options. Gear ratio choice is definitely something i seek input on.

I had intended to use Doug's or Hooker 1 7/8" headers and a 3" system w/ x pipe -suggestions?

TH400 is sitting on the garage floor and will be beefed up too - ideas welcome there too. I had intended to dyno the motor and match converter to suit torque curve/rear gear/weight etc but please suggest away...

98 octane pump gas is readily available around here too so I think I should be ok w/aluminium heads and 11 or so compression. As I understood 290b6 cam has been known to work ok with around 11:1 and a heavy car?

All input is welcomed. Need to get the juices flowing!

[jonmachota78]

I think I would go with the T2 if you're using the holley. RPM with a Q-jet.

[455-4+1]

Get another set of rims with a decent sticky tyre (not sure if you have MT ET Streets over there) for the track use to get you into the 11's. You want a 60ft in the 1.50-1.60 range at least for a street / strip car to avoid wasting alot of ET early on and a street tyre wont give you this.

Be sure to check your 98 over there. We have a 98 pump gas as well but when you check the rating (RON / MON RM/2 Blah Blah whatever they are) theres a good chance its not a "true" 98. Ours in NZ is nowhere near !!