are 305 and 350 blocks interchangable.. i have been told both ways and i just want to know the real answere

 

don't really understand the question but, if you're asking if the outside dimensions are the same then the answer is yes. a small block chevy is a small block chevy be it 305-350 ext.

You're lose would be roughly a 1/4 in loss in diameter of the cylinder bored being 3.740 on a 305 and 4.00 on a 350..... Strokes are both the same at 3.48 i think..... anyways you're losing 45 cubic inches of bore with a 305.

Definetly a big loss in displacement and a pretty good restriction for flowing higher hp through a 305. Although there are many 300+hp 305s and they are plenty easy to make 300hp out of with the right cam and a ported set of heads.

is any of this relevant? Maybe maybe not but, i'm bored and figured i'd type something up.

 

i have the 305 in my car now and havnt had much luck finding a 350 block so i just want to know if it was possible to make a 350/355/ect out of a 305. i know that i would have to bore the engine out but to what.

 

4 inches.

 

wtf was the last post about lol i typed 4 in i know what it is......


You can't just bore an engine to any magical # man.... if you bored out your engine 1/4 in on each bore you wouldn't have cylindrical cylinders at all and you'd have plenty kool combustion chambers (coolant passages would be your cylinder walls).

Max you can bore is .060 (60 thousandths) which would equate to a 310 cubic in motor when it's all said and done.

If you plan to do any block work like an overbore or align boreing then go to a junkyard and pull a 350 or 400 sbc from a vehicle and start there. A 305 just isn't worth the money if you need to do much machine work.

Btw no offense but, go to this site *howstuffworks.com

look at the internal combustion engine along with anything else car related you can think (forced induction has a good article). I love the site used to use it all the time a couple years back before i knew anything about cars. I still reference it ocassionally.

Basically find out more about what you're asking before you ask it, no offense intended we all have to start learning somewhere....

Btw go to the library after reading up at howstuffworks.com and rent some sbc buildup books (david vizzard is a very good author). That will tell you most anything you would ever need/want to know about engine building.

Btw a 355 is a sbc 350 with a .030 overbore (adds 5 cubes). a 360 is a .060 overbored 350 sbc. Or a stock dodge 5.9 liter engine if you wanna be technical but, i won't go there.

 

thanks

 

Wow - never thought I'd ever see anyone say a 350 block was hard to find - I thought 350's were everywhere! There's no boneyards anywhere close? 350's were in trucks, vans, and most all larger cars from the 1950's until tomorrow and beyond.

There's plenty around here from free to whatever cash you have - not that does you any good - unless you like looooong road trips. You can even spend the night here, but be warned, I have 5 children in the house!

 

i go to the junk yards and every car that i look in has had the engine torn out. and when i do find them the people usually want way to much money for them.

 

Here is a little trick for you, go to the junkyard and tell them you are looking for a core for your pickup truck. Dont mention anything about performance at all. YOu have a cracked block and need to transfer your guts to it. There are lots of people when they think that it has performance in mind will double the price. Same with the vortec heads. Go and ask for some truck heads from that year, not vortec heads. Just asking to be gouged,

 

A little off the topic of this exact thread...But you said 350's are all over...Does that mean a 350 engine from a blazer is the same 350 engine in the camaro of the same year?

 

More or less. The block is the same.

 

if they are the same then why can you get a 2 bolt main or a 4 bolt main?

 

At the factory they take the same raw casting and machine it to take 2 bolt or 4 bolt main caps. It makes no difference to any of the other parts, or to its suitability for street use which caps it has.

 

same deal here. i went to the local jy, and most of the crap they have, are tpi 305's they had one 350 with a tbi, he had no idea how many miles were on it, and he said they wanted 800 bucks for it. what a rip off. makes me just want to build my 305.