Rapid Robert
Well-Known Member
I will check with em, yeah that 2" exhaust restriction is crazy. not sue if I'd wanna risk 7K
cam/converter selection
- Thread starter Rapid Robert
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Open motors were already on a 2" pipe as were the crates. The difference for 2024 is the crates get a 2.25" pipe and both get a shorty header. If IMCA will let you, Schoenfeld can put a mopar flange on the same spec header the chevy uses. Your definitely going to want the shorty over the cast iron manifold. They are lighter, cheaper and make more power. If you use your 7 1/4 (I still think that is a bad idea when you are allowed a 9" floater) with 4.11 gears and run your 904 in second gear if you have a 1.45 second gear that will give you a final of 5.96:1. That's still a little tall even with short tires, but a lot closer than 4.11 and with out spending any money.
My opinion is you should run a manual transmission in high gear, a ford 9" floater rear end and build the motor to turn more rpm with an appropriate mechanical lifter cam.
Easy for me to say when I'm spending your money. lol
Rapid Robert
Well-Known Member
You're fine bro & very much appreciated! that's real good to know about the flanges as the restricted exhaust has been on my mind quite a bit. I will dig in & see if I can figure out if they will fit as it is real tight in there.
Rapid Robert
Well-Known Member
good info! Yes I see where they have changed the rules for the exhaust. I will call schoenfeld & see I can get that header with a mopar flange. I'm wondering if I should get the kit instead of the finished header & mock it up & see if it will fit my very tight chassis as is or it needs cutting/trimming as things are so tight in a early A body tho I ain't competent in that area (header fabbing). yes a header with a 2&1/4 outlet will be night & day ahead of a log manifold with a 2" outlet. Actually I have a 9" furd rear (not sure what ratio) & not sure what a floater is, that's been sitting & would need to be checked out/gone thru. the 7&1/4 still has 3.73's in it right now which'd be 5:41 in 2nd. I'm thinking I can mod the valve body so it wont shift into 3rd??? (also not my area). Hey stay in touch. RR
9 Inch Grand National Floater Rear End Kit, 31 Spline 5x4.75, 58"
This link shows an example of a floating rear end. The wheel doesn't rely on the axle to keep it attached to the rear end.
Better call IMCA first and see if they will allow you to use the header. If you can borrow a header for a chevy you can hold it in place to see if it will fit before you have one made for a mopar. The EQ port configuration has a little more spread between the center two exhaust ports so make sure you get a flange that will fit the ports.
I would use the 4.11 gear if you have one.
Rapid Robert
Well-Known Member
Yes I will call IMCA. I didn't know the EQ port spacing was different.
Bolt pattern is the same. The common wall between the center exhaust ports is a little wider and the shape is squarer. It is less effected by the headbolt. Take a look at your heads next to a set of non magnums and you will see the difference.
Rapid Robert
Well-Known Member
I talked to IMCA & they informed me that i cannot use a Mopar flange on those headers so I didn't even bother to call Schoenfeld. I called Summit & they informed me that I cannot refund my cam as it has been too long since purchasing, Maybe I can persuade them to let me exchange it expecially if I upgrade to a more expensive item. I'd like to go roller with all of the flat tappet hyd cam failures. OK so I need a different cam, can you give a suggested one or what numbers/specs should I be searching for, I'm a bit confused on this. thank you for your time. RR
You can't run a roller cam in IMCA.
When you get a minute you should read through the rules.
https://www.imca.com/wp-content/uploads/2023/11/2024-Hobby-Stock-Rules.pdf
Rapid Robert
Well-Known Member
Oh OK no roller cam. what specs should I be after along with the 106 LCA?
First, you have to decide what the safe rpm limit for your motor is. How hard can you spin it with out breaking it?
The maximum allowable rpm for Imca is 7000 rpm. Limiting the rpm to less than 7000 is probably going to limit the potential power output of the engine. That said whatever you decide is safe is what you need to tell the cam manufacturer when you call them for a recomendation. Also you need to tell them the intended use. How big the tracks are that you will race on. What your car weighs. Your experience level. Etc. Check with a few different manufacturers and compare their recommendations then go with whoever you feel comfortable with. Be honest with them, if your only going to turn 6000 rpm you don't want a cam recommendation for a motor that turns 7000 rpm. Good luck!
[Edit] P.S. I suggest you read over the engine section of the rules before you call them so you can tell them what you can and cannot do.
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Rapid Robert
Well-Known Member
Again bro you have been tremendously helpfull. the eng in the car is pretty much up & running & for this new engine I will gather all of the info you mentioned & call several cam companies & go with the best one. also I will hold off on doing anything with the high stall converter to possibly use it with the current engine till I find out what stall that it needs to be changed to. I wanna put them chebbies in their place/show em who their daddy is! Everything is very much appreciated! thank you. RR
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