I know, I know...ANOTHER thread about how much power an engine should be making, but I can't resist.

I bought this car a few weeks ago. I've discovered a few things through casting numbers and the previous owner, but not enough. PO did not do the swap.

The motor is a 350; Casting number: 10066036. Basic cheap 350 crate motor.
Heads are #3947041 'fulie' heads
Hooker Headers / Flowmaster exhaust
Accell Distributor
Edelbrock Intake; Don't know model
P.O. said car has a "small cam" Don't know what it is
Holley 650 carb (haven't verified model yet)

Obviously, without the numbers on the cam it is hard to guess, but just figure as mild as possible / worst case

Reason I'm asking is because I feel like the car should be much faster than it is. I haven't had a chance yet to drive it extensively as the interior is currently all gone awaiting the new stuff to be put in

Car does have a hesitation. Happens every time you press the gas, stumbles for a second then takes off. Pretty much falls flat on its face though. After that second or so, it does take off pretty good, but still doesn't 'feel' all that fast. P.O said car had a bigger cam but switched to a more mild one, and now the carb needs to be re-jettted. I know next to nothing about carbs, so...

Like I said, any idea on a HP/TQ rating (ball park) or even better, a 1/4 estimate.

It is an auto, supposedly with a shift kit, but don't know how to tell, but doesn't shift firm. Not like my old 4th gen that would chirp the tires between shifts.

Don't know what gears yet, haven't gotten around to taking the cover off and look, but stop (via RPO's) were 2.73's so I have to assume that's what they are. It's an '87 IROC

Here's a couple pics just for the heck of it



Last pic, pretty sure that's the choke and should be hooked to something!?

 

Looks like a performer intake manifold.
Heads are 64cc chamber 1.94 intake/1.5 exhaust. Not a bad set of heads, I'd machine them down though cause those chambers on stock pistons won't do justice.

We can't estimate your power without knowing the cam, if those heads are stock I can't imagine you are making much more then 350 horses at best with a small cam. Shift kits come in 3 stages, their isn't much firmness in stage 1.

I'd run a mid range cam, mill the heads, and regear. It wouldn't be hard to squeeze 400+ horses out of that setup.

 

More realistically, you're closer to 270 hp around 4500 rpm. And getting 375 hp isn't unreasonable, but the cam necessary for 400 is un-streetable.

 

You don't think flat tops and milled heads can get 400 horses to be streetable?

 

I've been building and testing SBCs for a living for about a dozen years now. 10.5:1 with '60s heads is gonna take an XE288HR, and that's too much for a street 350, whichever LSA you specify. The heads will be out of breath by 6000 rpm on a 350. And you'll need octane booster all the time. These aren't Vortec heads, they're stupid crap for the old dudes restoring Corvettes.
A COMP XE276HR will get you to 375 horses with good porting, an RPM-AirGap, headers, 1.6:1s, and so on. that's sort of driveable if you're a really tolerant person, and you use plenty of gear. If it's an automatic, it'll need at least a 2400 stall.

 

The faceplant from a stop is definitely a carb issue and can be either from running too lean (choke) or too rich (flood). Mine does the same thing until it warms up and even then simply dropping the clutch usually results in noticable protest.

 

Didn't mean to start an arguement or anything. All I'm looking is to be able to hang with at least a stock LT1, for now.

I guess I really have to get the carb issue taken care of before I can realistically get a feel for how fast the car actually is.

I would be happy with 300ish HP.

Previous Owner said the car has a rebuilt bottom end and rebuilt heads.
I know it's really hard to see exactly what was done without pulling the motor and taking it apart, but that's beyond me right now.

I guess my best bet would be to try to find a speed shop, or at least somewhere that builds engines (having trouble locating one) to take a look at the setup and take care of the carburetor.

 

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my guess would be around 290. What oil are you running in the car. The casting number shows it to be pre 85 making it a flat tappet motor so make sure when you do your oil change use high phosphorus zinc oil (normally found in rotella diesel engine oil) or else you will wear the lobes off the cam. Ask me how I know I'll show you pics of the cam and lifters.

Sounds like your carb needs to be tuned/rebuilt.

What is that large spring reaching from the carb area to the front of the head?