I got ahold of a drag motor. I am still working on what all specs the thing has but my question is can you have to much flow from your heads? The motor is a 350 bored and polished on the inside for more smooth oil flow. The heads are GM phase 6 ported and polished with I believe 2.08 ex and not shure about the int. but they are big. The cam is a Lunati ROLLER 50105 Ultimate Pro Street cam Good mid-range I was informed that the power range is from 4000 RPM and up. Needs 4200 RPM converter. Adv. Dur. 294/300 Dur @ 50 259/266 List in/ex 597/600 Lobe - 106, C/l 102.
The reason for all the info is to give you a better idea of the type of motor this was. i am looking to down size the cam to get this motor on the street because a 4200 converter is way to much for a street car as far as I know.
Can your heads be to big and flow to much air that it will cause problems if the rest of the motor is not up their with them?

 

No way does a 350 motor have a 2.08" exhaust valve. The bore is only 4" and the intake valve is always bigger than the exhaust valve on SBC heads. Maybe intake is 2.08"?

For the street, keep away from the solid roller stuff if at all possible too.

 

Too much flow? No such thing. Although some racing heads actually don't flow well until you get way up in the lift range. Usually, though, they still flow better than any stock or mildly modified head anywhere you care to check them.

Not enough VELOCITY? Yes, that's really more to the point.

Big racing style intake ports typically won't have enough velocity at modest street RPMs to keep the torque up.

It can still be made into a livable street engine with the right cam, but don't expect super low end torque with it, regardless of how small a cam you put in.

Remember to keep an eye on the compression ratio. With a cam that big they probably jacked it up pretty high (especially if it was on race gas). Smaller cams build more cylinder pressure and cam makie detonation problems from too much compression even worse.

 

Well after a good bit of reseach I came up with. The motor is a 383 and the heads have 205 intake and 160 exh. with 55cc cambers and flate top pistons with 4 relief valves. Still trying to figure out the compression ratio. The heads don't look to be ported much more then the casted version. Any thoughts on a good street cam with this set up? That 600 lift is well over what I need.

 

compression is gonna be preeety high with 55cc chambers and flat tops and a 383.

 

You'll be at a minimum off 11.42:1 compression. That's with a rather thick .039" Fel Pro head gasket and assuming the block was not decked (if it's a race motor it almost certainly was). Assuming they zero-decked the block you'll be up over 12:1.

You're going to need to address that or a streetable cam won't be the only consideration to make this engine truly "streetable." You'll need a piston with a -18cc dish to get compression down into the 10-10.5 range for a reasonable chance of using it with pump gas.

You're running into very common issues when trying to make a race engine into a street motor.