Currently running a Brock Performer manifold. My poor ole 350 is a DOG off the line, but after about 3-5 seconds, shes SCREAMING and ROARING, pushing me back in my seat.

Im wondering if a different intake will give me better off the line response??

(650 carb, 373 rears, headers, blah blah blah...all the mods done......) Unless this is a major tuning issue that Ive missed, Im thinking intake or cam modification.........

 

sounds like a carb issue to me.

 

All Ive done is adjust the mixture ( about a dozen times) These carbs run right out of the box, but Ive always felt shes running fat. Plugs looks generally OK but she does run a little sooty. Jets?

 

never heard of brock, unless you mean edelbrock? but it does sound like it would be a carb or fuel related issue.

 

It's those heads. It's KILLING your engine's torque curve. No sense in looking for a better flowing intake when your heads are just a giant bottle neck.

 

Dmnit, I had just convinved myself OUT of buying new heads!

 

Outside of the cam, I would rate the heads as the most important part of delivering air and fuel to your engine. Those stock 350 heads are just a bottle neck between the intake and combustion chamber. Anything you do from here on out will be limited by what those heads can flow.

 

I can do heads over the winter but its been a while since I tore a motor down that far. I think Im gonna start looking to see if anybody has any used heads for sale. Ive been told that 190cc is optimum, are there any other attributes I should look for? If I spend this kind of money and tear this thing down that far and dont get the performance gain I want Ill go bat$hit.

 

You'll want heads with 190cc intake runners, 56cc combustion chambers, and 2.02" intake valves for starters. Not all heads flow the same, so keep this in mind.

Really, a head upgrade in itself on a stock engine is worth around 20 HP. Now you add a good flowing set of heads to an engine with a mild cam, a port matched intake, headers, and a free flowing exhaust, you could see up to a 75hp gain, easily.

 

some really good heads that are really cheap are the L31 Vortec heads. they are almost dead nuts even with the LS1 heads in terms of flow, and you can find them anywhere from $400 a pair, down to $50. i'm picking up mine this saturday, for $38 a piece.

you'll want to stay away from the 906 castings (pre-'96), find the 8060 castings (post-'95). granted, they are slightly smaller than the specs that Jr. was saying (64cc chambers, 170cc intake runners, 2.02" intake valves), and can only handle up to a .480" lift cam without the heads being modified. you'll need a new intake for the Vortec heads as well.