Class help????

[Freddie]

Ok, I am ready to get my car to some races, there are a few minor details I knlow I have to change on it to make it legal for SS racing (mainly remove the sweet tubular k-member and lower control arms). Other than that I have a motor sitting ready to go, trans being built, wandering what class it will fall into...

1990 Ford Mustang GT hatch, with a 306 with canfield heads ( heads are listed on NHRA SS head volumes sheet). Having a new C-4 built cause I am sure being SS it will not be legal with a glide.

Question is will this car fall into a GT class? or am I required to run like a Modified class?

[Chris1529]

there are no minor changes to making a car a super stocker.

are you running a carb?
what year is the motor?

[Freddie]

Yes its a carb car.

Minor changes to how it sits now, it is already a race car I have been running NMRA O/C.

Have to change the front suspension a little, and put a c-4 in it in place of the glide.

Otherwise I am kinda in the dark on the motor.

[Freddie]

More than likely will run as a 69 302 cause I have a set of heads that match the tech bulliten for the 69.

Also wandering about what carb I need to run on this? I am currently using a 650 DP.

[SSDiv6]

Originally Posted by Freddie

More than likely will run as a 69 302 cause I have a set of heads that match the tech bulliten for the 69.

Also wandering about what carb I need to run on this? I am currently using a 650 DP.

There is no 302 4-bbl in 1969, the only 302/4-bbl shown is the Boss 302 engine.
If you claim a 1968 302W, then you can run a 4-bbl. The only legal 4-bbl carb for the 1968 combination is the Autolite.
You can only run a especifically approved Canfield part number cylinder head; P/N 18350;
refer to the following link: http://www.nhra.com/content/sportsma...9424&zoneid=85
You also have to maintain the runner volume of intake 167cc and exhaust 67cc
...and, the car will only be legal in SS/GT.

[Bill Harris]

Hummm.. You seem a little uninformed to be taking such a big step, but here are a couple of suggestions.

First, there is no 1969 302 engine that can use the Canfield heads. They can be used on a 1968 302 that was factory rated at 230 HP and has a NHRA factor for Super Stock of 230 HP with the Canfield heads. (220 HP with OEM heads).

Are your Canfields #18350's? If not, they won't be legal. Have they had any work done to them? If they have been ported you have to be sure that the port volumes don't exceed the numbers in the NHRA head spec. If they haven't been ported, you are not likely to be very competitive in class. Porting heads for super stock is very different than the usual "hog 'em out 'till you hit water" method. Combustion chambers must meet or exceed the OEM spec which is 49.5 CC.

The short block must meet the requirements spelled out in the engine specs for the 1968 302. Since it is a 306, it probably has the right 3.0" stroke and is no more than 0.070 overbore. Most importantly the pistons must have the correct configuration (flat tops with valve clearance notches) and the deck height/gasket thickness/chamber CCs must be within spec. You can use any cam and any intake manifold as long as it fits under the stock hood. The cam better be huge and you should be ready to spin that motor to 9000+ RPM.

You should probably claim the engine as a Mercury version so you can use a Holley carb. The Ford version only lists an Autolite carb, not sure which one it is but it might be a 4300 since it has an air valve secondary. The Comet/Cougar version lets you use a 600 CFM model 4160 Holley (secondary metering plate). You could use the ubiquitous 1850 carb, but it has to retain the choke horn and plate. The 4300 might be OK but I understand them to be very tricky to tune and hard to get parts.

A 1990 GT hatchback with automatic has a NHRA listed shipping weight of 3122 lbs. With the 68 302/230 engine you could run GT/IA through GT/MA depending on how much weight you want to carry. GT/IA would have to weigh a minimum of 2930 lbs with you in the car. GT/JA, min of 3045, GT/KA min of 3160, GT/LA min of 3275, GT/MA min of 3390.

You will need to make at least 400 HP to run the index and more like 480 to have the slightest chance in a heads up race. 500 would be nice....

Good luck and have fun!

[Freddie]

Bill: thank you very much for the info..

I have the right stroke crank, and have checked the pistons they are the correct ones as well. my heads are the 18-350's listed, but have bigger than stock valves in them 2.02/1.6's Cam is a big-un, and will easily support the 8500+ rpms needed. I have a 1850 carb sitting around here so that is not problem either.

[Mike Voth]

I'm not an automatic guy, so someone may have to correct me. I believe in SS/GT, you are only limited in transmission to the number of forward gears that were offered in the car the year it was made. You can run less gears than was offered, and no more. So, I believe you CAN run a glide, if you choose. I apologise in advance if I am wrong in this regard.

[Bill Harris]

Hey Mike, you might be right about running fewer gears, but the trans has to be same corporate make. So no glides in a Ford.

Also, I have been informed that the Holley carb for the Mercury version is a model 4150 with the center pivot bowls and secondary metering block. Sweet.

[Mike Voth]

Originally Posted by Bill Harris

Hey Mike, you might be right about running fewer gears, but the trans has to be same corporate make. So no glides in a Ford.

I gotta bring my damn rulebook to work with me! I thought that rule only pertained to SS not GT. Oh, well. I guess I bette stick with the stick!