Starting the design phase of my Stock Eliminator 1974 460 w/Thermoquad setup

I am at the beginning of a project I have dreamed of for years.

Last Sat. I bought the car that this Stock Eliminator engine will go into. It is a 91 Mustang Coupe, but I will convert it to 1989 trim so I can get the best weight break.

The car will be setup to run either a 5.0 EFI or a big block, but I want to make it run IHRA Stock GT class with a ' 74 460 with a thermoquad I have. The restrictions on the Tech sheet for the '74 460 is as follows:

The cam is only restricted to lift values: .442 int. and .486 ex. any duration, overlap, etc. allowed. (valve springs are limited to outer only, but must fit the same size retainer )

* Cu. In. will be around 472
* C.R. will be 9.20 to 1 (9.30 is max)
* I'm allowed a slight stroke increase, but to keep the cost down (somewhat ) I will use a stock crank and some 6.605 h-beams I have had for years. Custom pistons will be made.
* Head cc is limited to 88.7 cc
* Piston dish is limited to 14.8 cc
* Deck clearance is limited to .009
* Valve sizes limited to 2.090 In. and 1.661 ex.

The intake will be a stock cast iron D3 or D4 variety. Carter Thermoquad carb. 1 7/8 longtube headers.

The car: 3470 lbs with driver
C-4 trans (no transbrake is the only restriction)
Rear Gear ratio to be determined.

I need it to run 7.70- to 7.75 (1/8th) to run under the index of 7.85 @ 3470 lbs.

Can a 460 with these restrictions possibly have a chance at making the power to run these numbers?


The hood will have to changed to a stocker:

I was involved in building that engine combination for a GT Super Stocker and that turned out VERY well.
With a "stocker" you can barely modify the heads and are stuck with that iron 2 plane intake manifold however, you can still probably get to your goals.

It seems as though the intake side wouldn't be too bad given that a Thermoquad is a very large and capable carburetor. I think you'll have to do some real development in the camshaft, exhaust, cylinder head and intake department since those areas are the most open to modification. Getting metering parts for a Thermoquad can be difficult are you allowed to use the Competition Series or does it have to be a production carburetor?

DaveMcLain wrote:It seems as though the intake side wouldn't be too bad given that a Thermoquad is a very large and capable carburetor. I think you'll have to do some real development in the camshaft, exhaust, cylinder head and intake department since those areas are the most open to modification. Getting metering parts for a Thermoquad can be difficult are you allowed to use the Competition Series or does it have to be a production carburetor?

Dave:
I have a standard issue T-quad to work with. It has the D4 tag on it. Looks like it has been hardly used.

I know there are a bunch of guys running that combo in Super Stock, but I have yet to hear of anyone running a 1974 combo in Stock.
You are correct about the intake side. I don't see any restriction there. However, the tiny cam lift spec and super restrictive exhaust port will kill the power potential.

I know the cam lobes on those stocker cams are almost square in shape. Gotta be brutal on valve springs.
By my calculations I will have to spin the heck out of that 472 to burn enough fuel to make the power needed.

Luckily, they allow H-beams in Stock and as we all know, the productions cranks are plenty strong. So the short block shouldn't cause a problem.

The cam will be the trick here. From what I have heard, the valves never seat on those Stocker cams.

dfree383 wrote:Give Blair Patrick out of South Pittsburg, Tennessee a buzz and talk with him about building an engine, he has a whole bunch of Ford Stock / Super Stock building experiance.

There's a whole lot of tricks your going to need to know. your going to find that alot of things that work defy what you think is right with a regular HP build.

Thanks for the tip Dave.
You are correct about things that defy. I watch those class racers at the combo meets and are amazed at how they make their whole engine/trans/suspension combos work and go as fast as they do !

I still have to wonder why no-one has tried this 460 combination in Stock ? It seems with a factored 300 hp rating from NHRA, it looks on paper to be a soft rating. We'll see I guess.

Valve job will be extremely critical and doing some research on the flow bench will be essential. A few years ago I did this same thing on a 351 Windsor for a circle track customer who was restricted to a stock iron 2 barrel factory intake. I found several and tested them figuring on finding one that was better than the rest. They all were virtually identical! Good thing in your case, D3VE heads and spread bore iron 460 intakes are plentiful. It might not be very tough to find some NOS D3VE heads if you look around, something like that might make getting the valve job happening easier.

IMO that combo is a tough one for stock, if you would like a realy good piece you should consider the 1971 429cj. it is rated at 355hp for stock. gives you good compression, better carb, and way more cam. 515/515 solid. yes the oem heads will run you more but in the long run you will have a more competitive combo from the get go. just my opinion. in super stock there are many many more things that can be done to overcome the shortfalls of the 460 300hp as a general ruel to have a good piece in stock you need to make at least 150hp over the factored Hp, for super stock you will need to make double the factored Hp.

Regards Colin

ss 385 wrote:IMO that combo is a tough one for stock, if you would like a realy good piece you should consider the 1971 429cj. it is rated at 355hp for stock. gives you good compression, better carb, and way more cam. 515/515 solid. yes the oem heads will run you more but in the long run you will have a more competitive combo from the get go. just my opinion. in super stock there are many many more things that can be done to overcome the shortfalls of the 460 300hp as a general ruel to have a good piece in stock you need to make at least 150hp over the factored Hp, for super stock you will need to make double the factored Hp.

Regards Colin

Thanks Colin !

That CJ combo would put my coupe in S/GTA (natural class) but GTB would be better. In GTB the wt. would need to be 3195 lbs. (3365 with me in it)and the index is 7.50 1/8th and 11.65 1/4 mile.

O.k.... now that has my interest.

Wonder how hard it would be finding a carb with the correct casting numbers ?
I also would imagine finding 39 year old CJ heads will be hard to find that have not been cut on.

there is a set of stock uncut cj heads for sale here or on the other 460.com form

Alan, the carb does not have to be correct casting just proper bore size and venturi. Kwick fuel just got a 780 vacuume secondary replacement for the 3310 holley carb approved for NHRA stock and super stock as mater of fact I have one and its a great piece. IHRA usually follows suit with NHRA as there are a lot of cars that cross over so that should be a non issue. The one thing that may be hard to find would be the manifold. Colin

Isn't the manifold the same as the "boat" intake?

res0rli9 wrote:there is a set of stock uncut cj heads for sale here or on the other 460.com form

I think I found what you are referring to....they were sold
Thanks for the tip tho.

ss 385 wrote:Alan, the carb does not have to be correct casting just proper bore size and venturi. Kwick fuel just got a 780 vacuume secondary replacement for the 3310 holley carb approved for NHRA stock and super stock as mater of fact I have one and its a great piece. IHRA usually follows suit with NHRA as there are a lot of cars that cross over so that should be a non issue. The one thing that may be hard to find would be the manifold. Colin

Thanks Colin.
That's good to know.
Now all I would need are a D0OE-C intake and some D0OE-R uncut heads.

dfree383 wrote:The intakes realy aren't that hard to find and as far as heads, they are around and not that expensive. Not D3 cheap but the castings are typicaly way cheaper than buying a set of P-51's.

I found a set of D0OE-R heads on flea-bay for $ 1,555 plus shipping.
Hard part will be to find a set uncut in any way tho.

is this the intake you wont
https://www.429-460.com/stuff-for-sale-f1/dooe-cast-iron-intake-t7100.htm

I am not sure if you are all set on this or not but, I have an NOS SCJ intake in the box and 2 sets of virgin D0OE-R castings just back from thermal cleaning and magging.

I will sell 1 set of heads and the intake for $1500.00 plus the shipping. One set of heads has the "SPEC " date codes not that it matters.

Thanks, Mike H.

mtburger wrote:I am not sure if you are all set on this or not but, I have an NOS SCJ intake in the box and 2 sets of virgin D0OE-R castings just back from thermal cleaning and magging.

I will sell 1 set of heads and the intake for $1500.00 plus the shipping. One set of heads has the "SPEC " date codes not that it matters.

Thanks, Mike H.

Would the intake have the casting number D0OE-C ? If so, got pics?
Head date codes mean nothing for this application...just the casting numbers.

dfree383 wrote:

res0rli9 wrote:is this the intake you wont
https://www.429-460.com/stuff-for-sale-f1/dooe-cast-iron-intake-t7100.htm

can't use that one it's been modified.

I have an extra CJ qjet manifold that unmodified if that's the route you want to take.

Dave:
If I go the '71 CJ route, it most definitely would be the SCJ Holley setup. NHRA factors it at 355 hp with a solid flat tappet cam. On paper the heads and cam specs looks good. (better than the hydraulic cam spreadbore CJ)

Hello.

The casting number is D0OE-9492-C

The picture was taken in a dark basement with a cell phone.

It is a nice piece, it is still in the factory packaging and it was sealed in the bag until I got it.

Thanks, Mike H.