Ok I have a question, does anyone know what the max power someone has got out of a 305 with out using any form of forced induction or giggle gas? I heard a rumor that someone got over 400hp on pump gas from one. I don't know why but I think it would be interesting to see just how far a 305 could be pushed safely.

thank you
chris.

 

That oft-quoted 400 HP magazine 305. Amazing how often it comes up.

"The rest of the story" is that right after they recorded that 400 HP on the dyno, the 305 puked a rod out the side of the block.

So, the "safely" part is more like 350-375 HP. In order to get horsepower, you either need to increase torque, or increase RPMs. The only way to increase torque is to pack in the fuel and air - after a certain NA efficiency is reached, you only option is artificial respiration (turbocharge, supercharge, giggle juice).

Increasing RPMs is accomplished by more cam duration. With increased RPMs comes increased stress on the rods, particularly the rod bolts, and valve train. ARP rod bolts should be considered a must for anything over 6000 RPMs (sustained). Aftermarket rods if you're going above 6500 RPMs or so. Very expensive valves, springs, and rockers.

By the time you get to this point, you're putting the same $'s into the engine for less return than you'd get out of a 350. You'd be replowing old ground, reinventing the wheel, going where numerous men have gone before. You might think you're "unique", "different", "going down the road less traveled" - fine, but quite frankly, nobody else will care. During 4 years of driving and racing a hopped-up 305, I had exactly two people ask me if I had a 350 - and both of them were Ford guys.

But, hey, it's your car, your money. Do what makes you happy.

 

LOL, part of me thought it would be fun and if I had that kind of money lying around, I totally would go for it. I was just more wondering what people have gotten out of a 305.

 

One member built up a supercharged 305 (Procharger, if memory serves) that was in the 11's. But, he had to do all that stuff above, aftermarket rods, forged pistons, worked over heads & valve train. He took that engine out, put in a NA 434 and is over a second and a half faster.

Another member got impressive performance out of a 305, but he also lightened up the car. He had a similarly-built 350 in it for awhile and was significantly faster (that engine had problems, though). He now has an LS1 in it (still waiting to see track results from that swap).

If you are starting with a stock 305, I always say you can go faster for a given, limited amount of dollars by bolting stuff onto the 305 than you can using the same dollars to buy, build, and support a 350. But, that's a special case assuming you do not spend any money on the 305 shortblock (bore, pistons, rings, bearings, crank, rods, etc.). Exhaust, heads, cam will cost you less and perform better than spending the same bucks buying a 350.

But, as soon as you start talking about spending money on a 305 shortblock, forget it - go get a 350 (if HP/$ means anything to you).

 

Five7kid's right. I well understand the desire to make something of the 305 you have, I remember being there myself, long ago. But once you go 350, you'll never go back.