305 to a 350

[84aLkI]

i have an 84 el camino with a stock 305 some one told me i can change the 305 block and throw in a 350 block and use all the same parts i have on the 305, heads intake carb EVERYTHING i'd just be switching the block and would still be able to pass smog and gain some H.P is it true??? it like sounded like BS to me im sure i'd have to make some changes can someone give me some good ino cause i AM intrested

 

[85 Cutlass Brougham]

It is true to a degree. You can bolt the stuff together that way, but compatibility issues may exist depending on the 350 used. I would not run 305 heads on a 350 though as they are too restrictive. Plus, with most flat top or mildly dished 350 pistons, the small chambers of the 305 heads will build too much compression. You are better served with a complete 350 long block instead of a short block with 305 heads. My car is an example of a 350 with all 305 bolt ons. Remember that in most cases, so long as you stay within the same engine family switching to an engine of a different displacement is pretty straightforward. You just have to know a few specifics that relate to the minor changes and improvements the engineers made that may make some parts incompatible. With an engine like the SBC that remained in production from 1955 to 1999(IIRC), there are bound to be a few minor differences. If you post the year of the engine you wish to install, I can give you a rundown of the complications (if any) you may encounter. While ANY SBC (except some early 265's) will bolt right in to your chassis, not all used the same accessory drive mounting positions, and engines built before 1969 or 70 may lack provisions for some accessory systems. The safe range for your car is about 1980-1986, but earlier or later engines will fit with the right minor pieces.

 

[DETROITBOY27]

I did a swap in my wife's 79 elcamino and put a 290 hp crate motor in it, and the transmission blew about 500 miles later. Just a little fyi, the 200 transmission won't hold alot of extra power