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Camaro Engine Rules


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To start off, I'm building an '86 Camaro for CMC. It currently has no computer and a 350. I have...

600 Holley carb

HEI (non-computer)


'83 305 shortblock minus intake.

'92 305 TPI longblock minus intake and injection system, wiring harness etc.

'97 305 Vortec shortblock (truck)


My understanding is either motor (83 & 92) is legal with the update/backdate rule.

I've search and found no real answer to my questions tho....


If I use the '83, I would upgrade to the spec cam and intake.

Question: Do the head I need have be be the same as what came with the block originally? If not, what heads can I use/would be best?


If I use the '92, I would upgrade to the spec intake and carb.

Question: I believe this would require modifying the bolt holes in the intake to match the TPI heads. Can you run a carb set-up on a TPI motor? Is that legal, or do you have to use the entire TPI setup.


If I use the '97, replace the cam with the spec cam or a TPI or TBI cam.

Question: Is this even remotly legal? This casting number was added to the approved list in ASedan. Again, what heads could be used?


Also, I currently have headers, and CMC requires stock manifolds, so I have to hunt down some manifolds. How essential is it that the manifolds are the same that came with the heads, or will any stock Camaro (82-92) manifolds work?


Sorry for the 20 questions, but I only want to build my motor once.



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Hi Gary,

You've posted in the right place and will be able learn from what some of these guys have done. If you have any other questions feel free to give Adam Ginsberg or myself a call.


Hope to see you out at a Texas track soon!!!

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From a legal to run perspective (not being a motor expert here...)

You can run any pre LT1 heads that were offered in a production 3rd gen camaro/firebird. I can't tell you if there are any that are better than others...my hunch is it really wont matter. You can also run the spec carb/intake/cam on an otherwise stock TPI motor...the only difference there might be compression ratio vs the non TPI cars.


I don't know what the specifics of the vortec motor are...I suspect there are enough differences there that it doesnt match the earlier 305s...but I dont know, it might be all just heads and other external stuff. Somebody around here must know.

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Gary, no question...go with the TPI setup...I even have the whole injection setup for sale cheap...better torque, powerband, etc....don't even bother messing with the other alternatives...that's 16 years experience racing Camaro small blocks talking...rp..if you want a long drawn out explanation feel free to call me 831-622-9024

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We've got some manifolds off a 90 RS 5.0, we went with headers on a street car. The manifolds are year specific due to the dipstick, ie you need to make sure that you use manifolds from a car with the dipstick on the same side as the block you are using. (Hence having the buy headers...)

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Thanks for the replies. That gets me off in the right direction.


I currently work at a machine shop, and my definition of a "stock" motor may differ than what the rules intend. We routinely suggest upgrades over OEM for most street engines we build. These items don't necessarily add hp, but usually add life to the motor. The stuff such as porting or bowl work is pretty obvious that it is prohibited.

A few gray areas on things that arnt quite OEM spec but yet are things that I would like to do...


Brass freeze plugs instead of steel

Moly rings instead of cast

Hypereutectic pistons instead of cast al.

(no coated skirts)

High volume oil pump

Double roller timing set

H Rod bearings

Zero decking the block


ARP Rod bolts - yes 8.17

Balancing - yes 8.16


I know that the main emphasis is the 230/300 rule and keeping costs down, but these things don't really have a power advantage and arn't that much more expensive over stock (unlike the road-racing oil pan )


Am I worrying about rules too much?

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First off, you are not worrying too much so thanks for the questions.

You can do everything you asked about ie: rings/bearings/freeze plugs/pistons/pump/chain/ARP/Balance.

Mustangs actually used forged pistons in 1987 so for the Fords you can go forged if you want to ( just giving you an example even though you are running a chevy).

Good luck,

Tony Guaglione

CMC Director

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