i just got a 305 and i want to get some nice hp out of it does anyone know if you could put a 350 crank in it? if so let me know what other things i could do to it

 

the only difference between a 305 and a 350 is the bore size...
same crank and rods..

 

welcome aboard, be carefull when you mention 305 and H.P. in the same post, there will be a whole parade of "just get a 350" people around here. I got where I don't even ask that question any more, I just read the other performance post's and then make my own decisions. there are a few people who are comfortable with the ,you know what and H.P. question but not many.

my opinion is, if you have a strong running 305 and it still has some life on it, start adding some bolt on stuff and then when the time comes you can just transplant that stuff onto a 350, but theres no need to pull a perfectly good motor just to put a 350 in unless you want some "real" horse power.

 

NY,

Congratulations! You've found us.

The 305 and 350 have the same 3.48" stroke, so changing the crank will not have any effect on displacement or power.

Well, that's not completely true, since the 305 crank is balanced for slightly lighter pistons, so a 350 crank without counterweight trimming would not be great for overall dynamic balance in a 305.

To change the displacemetn of the 305, you'
d have to install a 400CID crank, and modify for all the balance problems that accompany that, or use an aftermarket crank designed for an internally balanced engine like your 305, or enlarge the cylinder bores. The practical limit of bore for a 305 is about 3.800", and that can only be done on some better castings that have adequate material and very little casting mold core shift. At that point, you would increase displacement to around 316 CID with the stock 3.48" stroke.

You'd probably get a greater power advantage by focussing your efforts on the heads and valve train. If the rotating assembly of the engien is in good, servicable condition, you can realize some respectable power gains from improving head and valve flows. There are some very potent 305s represented on the Boards. Search for some of them, compare their ¼-mile timeslips to those stock 350s, and decide what you want to do.

We'll be here to lend some experience and adavice, and help you spend your disposable income.

 

yup you can modify ur 305, and yes it will perform. you will get a lot of **** for modding the 305 or when u do get it to be really quick people will jsut say u wasted ur time. dont listen to it. if people wanna preach displacement talk to import guys, but they arent gonna listen to the gibberish either and before ya know it theyll be blowin ur V8s doors off. with that said start with free mods, IE: throttle body coolant bypass, cut the bottoms off the air box, port the plenum, get rid of excess weight, bump up the timing to 8-10* advance, get urself a used LT1 cam or you can go aftermarket, depends what u want for a power increase. headers, port work, suspension mods. some of those mods are for the TPI engine not sure if u got carb, tbi or TPI. they all have their ups and downs.

 

thanks for all the info guys looks like i am going to do a 305 after all