I know its not a science and it depends on drive and traction and temp, but I'm just lookin for a opinion. Heres what I got

87 Firebird
V8 305 LG4 , 4 Speed Automatic
42,000 miles
Computer Delete
Edelbrock 600 cfm Electric Choke Carb
Edelbrock Performer Intake Manifold
14" Open Air Cleaner, KN air filter
Comp Cams Roller Cam 260
Comp Cams Roller Lifter
GM Aluminum 1.5 Roller Rocker Arms
New Springs and Retainers
Double Roller Timing
New water pump
Edelbrock Headers and Y pipe
High Flow Cat
Hooker Cat Back
Auburn POSI with new ring and pinions
Stock 2.73 gears
BM Megashifter(rachet)
165 thermostat
Fan on at start
New HEI Distributor set at 35
I'm thinking the HP at the rear is at 210 and about 300 Torque
I Believe the car is around 3200 lb
O and I have regular tires on it
running 89 with Octane booster
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It probably weighs more than that, certainly more going down the track. Mine is over 3500 with me and 1/2 tank of gas in it, trunk emptied.

The 2.73's, stock converter, and street tires are going to hurt. You're probably looking at low 15's.

 

Your car is probably closer to 3500 pounds. Mine is stripped right down and the race weight is still close to 3200 pounds.

I'd also say low 15's. If you want to know what it will run, take it to a track. A guess is just a guess and means nothing since no 2 cars are the same.

 

If you really do have 210RWHP (unlikely) and the car weights 3,200(I highly doubt it) the best you could possibly run with a perfect launch, perfect matched gears and stall would be 14.45

210RWHP would put you at 247 flywheel HP which is a pretty dramatic improvement on the LG4 for the mods you listed....

I would say mid to high 15s... those gears are crap... and with the tight stall that will hurt you bad.

Like they say, just take it to the strip... it's the best way to find out. It's important to get a starting point even if it's not as fast as you hoped. I was guilty of overestimating my first engine build as well.

BTW don't bother with good gas or octane booster if you aren't pinging, it will only slow you down.

 

I need the extra octane, because the speedshop told me it detonated running just 89. Thank you for giving me a realistic weight.

 

You do NOT need ocatane boost... if it's detonating, either your timing is far too advanced, or something is very wrong. Check out your timing first... might be able to pick up some lost HP.

 

Getting dyno tuned this week i'll see whats going on when it gets back.

 

with that intake and cam I think some decent heads would really help you out (that and 45ci more)

 

I was thinking AFR 180cc heads either next summer or later on. They will cost about $1200 and another $800-1000 to install.

 

i say you run 15.9-16.0 around 85mph, but go to the track and find out....