loooking for some educated guesses hear. I swapped out the LG4 and put in a 250-275 horse mild performance 350 with headers, 3" exhaust and a pro built Q-jet. The problem is that I am still running my LG4 intake. I ran it at the track last weekend and ran a best 15.2 @ 91. My best times were accomplished while shifting just under 5500 instead of my 6200 redline. How much power will I make/quicker will I be after an intake swap. I was thinking og using a Weiand Stealth.

 

that may not do anything at all... what cam is in it? a 151? a 929? do you know?

 

From the build sheet:

# 115848
050 Dur 214/224
Adv Dur 280/290
SAE Dur 288/298
Camshaft 28lif 443/465
Lobe 107/117

 

By the way -- New best Time:
2.50 60'
15.097 @93.1 mph

 

That's right near 200 HP at the crank, maybe a couple more... less than 220 at the crank. Just for reference, a "rated" 190 HP (crank) L69 car did 15.2-15.3 off the showroom floor; a "rated 205 HP (at the crank) LB9 did about the same.

The other day my formerly L69 motor, with different heads & cam & headers, but still the stock intake (same as your LG4) and stock carb and stock air cleaner and all computer controls installed and operating, dit 208 HP at the rear wheels, which is around 260 at the crank.

So, I'd say, based on those numbers, you have a way to go before the intake is your main restriction. You might pick up a little, but that's not your bottleneck just yet.

 

using a formula that derives hp from mph and weight, I got 230 hp on a 3675 car (w/ driver) on a 93 mph run