Thread: how to make power on a chevy 305

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hello, i have a 1988 chevy pickup, 2wd, and im looking to make some horsepower off the stock 305 motor, if you have any suggestions please let me know, i know that most people prefer the 350, but im interested in pulling off the impossible, 325horses from a 305 motor, plz try and help me out here, thanks for your time,

Buy a rebuild kit for a 350 then replace the block with one that the parts will fit in.

The 305 won't hold up to a blower or turbo or nitrous. You need 4 bolt mains if you want to build horsepower and the 305 doesn't have them.

It'll run better with an Edelbrock performer cam and intake and headers but that won't even be close to the HP you want from it.

If there was a practical way to get 325 HP out of that engine it would have been done long ago and there would be a kit and lots of magazine coverage.

A lot of things have been tried to help these engines but you get much more for your money if you start with a better engine.
AL

Go to the internet and type in 305 chevy buildup. It will tell you how to get 325 HP out of your 305.

Originally posted by chevy 37
Go to the internet and type in 305 chevy buildup. It will tell you how to get 325 HP out of your 305.

I went to that site B4, Diddent they do it with a stock 145 Hp Camero engine?

Yea they did.. It worked on mine, but I used a different cam and got close to 300, but I also had it bored .060 with high compression pistons.

The Al Show... 4 bolts are over rated. My 86 El camino ran 13.60s with a mild 305.
Its no secret that its easier & cheaper to build power from a 350 than a 305, but its easier to make power with a 360 than a 318, people continue to use the 318 anyway.
I had a blast with my 305, there was a pumer goin around town that I was tellin people it was a 305, but was really a 350 LOL.
BTY its for sale .

Stepside
The 305 isn't a bad engine and with the Edelbrock parts that I used on mine you can make it perform very nice for a street car or a pickup like the German guy has. For a reasonable amount of money you can get some worthwhile improvements. after that you have to spend an unreasonable amount of money for much smaller gains. It's not a good choice for someone looking for megahorsepower. I've owned a lot of cars that were great on the street but would be embarrassing at the strip.
But I only go to the drags to watch. I'm the kind of guy that would rather have fun on the street than have a bad day at the drags.
You can have fun with a warmed up 305 but If horsepower is your priority then do it right. Toss the 305, forget the 350 and get a big block.
AL

I think you may have the best idea for our German friend. Lie about your horsepower like the rest of us. I doubt he'll get it dynod anyway to get a true figure.It won't make that much difference in a pickup truck anyway.

hey csf... what size valves in your 58cc heads? were the heads angle milled? were the springs stock, barrel, or oversize? summit cam, hyd or solid? did it dyno up at 325 hp? were your pistons forged? cast? domed?

don't get all outta shape man. I've been contemplating putting a 305 in my old roadster and I've never built a 305 anything. With 4.56 gears, I don't doubt the wagon pulled like a bear. That got me to thinking about how that combo would work in a 2500 lb. car.

I just used the performer cam and intake on mine with a set of headers and I'm getting almost 400 horsepower. Oh ya I also put in a new timing set and a holley double pumper 600 carb and new spark plugs. I just added all the extra horsepower that each part claimed in their literature so the dyno wasn't nessecary
AL

Good one Al !!!! used one of them there advertised horsepower gain dynos, huh??? Geez, guess my 514 must have about 800 horse, huh????

You got an 88 so it's injected, roller cam, and truuuuuuck heads. Unless you want to spend big bucks, I'd take the injection off and change heads and cam. Chances are it's probably a dish top piston engine but you can get 300 horse with dishes. I built a 305 once with a good set of 283 heads, a Comp 280 H cam, and performer RPM intake. You'll have to change it to HEI, for fire. You'll need an old style vacuum advance distributor. Pull the pan, then timing cover. Get a Cloyes Double Roller chain and gears. I put 1.6/1 rockers on too. Now with that big of truck and that small of engine you'll need a set of gears and a stall. 3.42's and a 2200. If you do this yourself, you should get in it for about $1200. you go injection your looking at a bigger newstyle head, bigger intake, bigger injectors, bigger chip, bigger bigger bigger. I'd just use the proven oldstyle cheap power man. It's gonna be way easier. I just did a 90 chev 4x4. We put a 327 in it out my buddies 67. All you need for your transplant is a different throttle/kickdown cable bracket, headers and a few minor festeners. Plus all the stuff above I said to use.BB
Oh Yeah 325hp! Don't forget to adjust your shift detent cable or you'll burn up the trans like a G at a white womans funeral.

Either we haven't said what the German wants to hear yet or the guy died after his first post.

My good old friend that taught me alot of high perf had a 68 Camaro. It was kind of ratty to the purists but it was a nice street car. Any way we built up a 305 similar to the one in my other post I just made and it would pull the front left cake with polyglass G/T redlines, a set of slapper bars and an M-20! Some guy bought it and still pounds it all the time! pound for pound, 305's are way under rated. The only guys who don't like them, never had one. And not all of use can afford mega buck crate engines. Some talk about working on cars, and some actually do. BB