There's no way to answer that, but putting 305 heads on a 350 would increase compression ratio by about 1 point, which usually increases hp by about 20.
a 350 will produce around 250 hp, and a 305 about 200 hp
Base 305 4bbl (170 hp), optional 305 TPI (215 hp) or 350 TPI (225 hp)
The Monte Carlo SS didn't have a 350 in 1987, but the 305 had 180 hp
The fastest 305's were in the Monte ss's & they only got 185hp, best option is always to go for a 350 swap
165 HP for LG4 carb 305. 190 HP for LB9 TPI 305 220 HP for L98 TPI 350
That totally depends on how MUCH MONEY your wanting to spend. Myself I wouldn't spend any money on a 305 engine. I would get me a good 350 engine to build.
20HP/ Horsepower. The 350 has 20 Hp more.
Several engines were available. The 305 cid (gas) had 170 HP and the 350 cid (gas) had 210 HP.
the 305 is not a hot rod engine. it is possible to get around 350 hp but don't waste your time or money. the bottom end is not strong enough to take much hp. try to locate a 350 cu in 4 bolt main engine and re do it. marlin
if it has the 350 CI engine it has 250 HP @ 4400 RPM if its the 305 CI engine it has 235 HP @ 4200 RPM
250 ci 105 HP, 305 ci 140 HP, 350 ci 145 HP, 350 ci 165 HP, 400 ci 175 HP.
gm says a stock 350 z28 has 245 horsepower a 305 has 230 hp