okay, i had someone give me a 350, but its torn ALL apart. pistons out the block, etc. well, i got all the parts to rebuild it, but for some odd freaking reason, the pistons will NOT go into the block. you put the compressor as tight as it'll go, attempt the tap the compressor into the cylinder the slightest it'll go, and all the compressor does is bounce around. never seats evenly and i'm getting fed up with it. royally. well, my current motor, is a 305. either head gaskets are gone, or intake gaskets gone, or both. bc i have water leaking from the back of my block. cld even be a freeze plug. anyway! what i wanna do is this. i wanna take the brand new 350 crank and main bearings and rod bearings out the 350, and put in the 305. i know almost for a fact the rings are good. but i did spin a main a while back. atleast thats wut i was told. idk. hence the reason the for the swapped crank. also, i wanna put the brand new cam from the 350 in the 305. from the cam on up. BASICALLY! ONLY thing that will be 305 will be the cylinder bore and pistons/rods. read online the crank would work. dnt know about the rest. i'm sure someone's either tried it to no avail, or knows someone who tried it and it went perfect. hopefully the second. THANKS!



the 305 will have from a 350:
new crank
new main/rod bearings that came with crank
cam
lifters
pushrods
all top end gaskets
heads
intake
and a stock 4brrl rochester quadrajet carb that fits that intake.

 

You're trying to put the compressor into the cylinder?

The 305 and 350 cranks have the same stroke and are from the same casting, but they're balanced differently. You can't swap them without rebalancing.

The chambers on the 350 heads are much larger than the 305's, you're going to have lawnmower compression.

 

i was waiting for that response about the compressor. haha. not the entire compressor. just the very bottom so the rings won't release before they leave the compressor... and thats exactly what they do regardless. i'm boutta just give up and say screw it and try to find a 350 already built... and i have EVERYTHIGN to rebuilt it. whole new gasket set, brand new msd distributor, new oil pump, new cam, new crank. all that jazz.

 

No part of the compressor goes into the cylinder. You have to hold it tight against the deck while you insert the piston. If the block is chamfered it will be more difficult to get the bottom oil ring in without it popping out. What type of compressor are you using?

 

we have tried that to no avail, maybe it wasn't tight enough. my bro should be coming tomorrow to help/see bout it. maybe he can get it. the compressor, its the tin wrap around one. with the square allen wrench thing. the first we had, you'd try to get it tight enough and it'd make that one last snap and then bounce back so it wouldn't stay tight. got another that does better, but just won't allow the oil ring to slide in.

 

Try a different compressor. The wrap-around style, especially the cheaper ones, are garbage.

 

a few questions.

do you have the right size pistons?... will they slide in with no rings on?

are you making the compressor to tight so the piston will not slide threw it?

 

To my knowledge islt is the right pistons. If i temmeber right we did try to slide em in with out the rings. And the compressors tightness, no. The compressor slides around the piston as u try to tighten it more. Haha. Wonder if its not tight enough.... Any ideas how? We've held the rod and tried to tighten it n put it in the block and it didnt work. It was TIGHT but the piston slid straight out.