I dunno...Ive never seen a cross-rammed, solid lifter, 11:1 compression, 8000rpm, double hump headed 305...but thatd be interesting...or a waste of time towards a learning experience at least...haha

Build us one then tell us the difference...cmon...ya know you want to...

But darnit...good luck finding a 3 inch stroke chevy crank.
Then good luck finding the right compression height for your pistons.

Yeah..i tried to build a 302...but it was gonna cost more than it was worth.

God bless
-Shred

The problem with the 305 versus the 302 as the factory built or builds them is the 302 will kick the 305's butt because of physical constraints within the design. Physics tell you they should perform identically. The problem is the engineering design solution takes you from the general condiiton (physics) to the specific condition (engineering) and while these engines are very similar, their differences are significant and one in paticular, valve size, cannot be overcome.

As they come, or came in the case of the 302, the 305 is port volume and valve size limited. If you used the same valve lift and duration the 302 would always perform better because of its factory heads versus those of the 305. You would have to put identical carbs, heads and arrive at identical compression, and cam timing before the 305 would begin to keep up to the 302's ability to perform work. The two would be able to perfom work as the physics indicate, but there would be an RPM difference as to where the torque and horsepower peaks occur. This would be a function of stroke, where the longer stroke engine all other things being equal would peak at a lower RPM. All things being equal except for the cam, the differences as to where the power peaks occur would be close together for a mild cam and get further apart as the cam timing became wilder.

Now you can put different heads, different cams, and different valves and get different results. But you'll hit design limiting constraints on the 305 sooner than the 302 because the smaller bore of the 305 (3.74 inch) will run out of space for valve diameter increases before the 302's 4 inch bore will.

Getting the most out of either requires gear selection that takes advantage of the engine's power curve shape. The 302 would prefer lower gearing to take advantage of its higher RPM power peaks. The 305 would like a higher gear because its greater bottom end torque will overcome the available tire traction sooner than the 302. So there is the need to move that constraint, among many others, around the power curve.

Now one could say yeah, I'll just get stickier tires for my 305 and while that's true, you need to keep in mind the bigger picture of what's going on. As you can do the same thing with the 302 and go to stiffer gears and the whole thing just keeps ratioing up till you run out space or materials strength to make further changes. Which brings you back to valve size, all other games being played out, the 305 hits the wall on valve size sooner, therefore, it will run out of breathing capacity before the 302.

Bogie  

Bogie

You need to think of a 350 as simply a stroker 327. A silly quarter inch more.

An interesting thing, since the 4 inch bore of the 327 and 350 is the same, it's easy to use the same head on either engine. Now to show you how breathing really controls the optimal output of these rather closely sized engines. If you build a 327 and a 350 with the same head, cam, carb, and compression each engine puts out almost idential horsepower and torque, just at different RPMs. The difference being that the 350 wants more breathing capacity, so when constrained with say the 300 horse 327 cam, it also peaks out at 300 horsepower. It just does it at several hundred RPMs lower. However, the 350 shows greater torque sooner than the 327 in question. While 350's torque peaks sooner it starts to drop off faster as the breathing becomes constrained by the camshaft timing, thus the lower RPMs of the horsepower peak which is the same amount as the 327 at 300-305 hp. So the problem gets to be one of gearing if everything on the engine is constrained.

What this tells you is that it's the amount of mixture you can get thru the engine that dictates its power potential. As cam timing gets wilder but remains the same for each engine; the 327 will give up bottom end torque sooner than the 350 because the port velocities fall off. At the  top end the 350 will fall off sooner as the cam timing and ports reach their maximum capacity.  Geared the same, the 350 will come out of hole harder and run out of steam going thru the traps. The 327 would come out of the hole less aggressively, but pull harder in the traps.

If porting, carburation, and cam timing are unconstrained, the 350 will out perform the 327 simply based upon the greater displacement, as adding more and more cam timing or port size will simply reach a point where the 327 is breathing everything the engine displacement will allow, yet the 350 can still use more cam and more porting before it peaks out. Of course this only works for engines of similar size, obviously you can't get the power from a model airplane engine to drive a ship no matter how fast you can turn it. Which is a way of saying that in the end physical size will determine a limit. Out there somewhere is a place where you can't make a cam that keeps the valves open long enough, nor can you make a port big enough to support the mixture flow either engine needs for life say over 11,000-12,000 rpm.

Bogie  

hey that answer's my question.so the 350 is the better motor is what im gettin no matter how many r.p.m a 327 can turn it all boils down to dislacement i realy had my hopes in the 327 but i'l take your word for it because i see now u guys da** sure know your math once again i sure appreciate everything guy i guess (there's no replacement for displacemeent!!!) once again THANKS  

All things considered the bottom line is that when you go to the wrecking yard looking for a rebuildable core, you're way more likely to find a 350 than you are a complete 327 or a 307 crank to back build a 350 to a 327. Not that it's impossible, but it's been a long time since 327s or 307s have been built. So the simple solution is just use a 350.

From a performance stand point, there's no inherent advantage to a 327. Nothing more magical about a 4 inch bore and a 3 and a 1/4 inch stroke than a 4 inch bore and 3 and half inch stroke.

Bogie

technology has come too far to build a low tech 327 of yesteryear
today a 377 is yesterdays 327
destroke a 400 before you destroke a 350
imo a3.48 or 3.5 inch stroke is as small as i wana go  

Whichever way you go in my opinion, Chevy Small Blocks Rule! I suppose it depends on what you're looking for. If the car came with a 327 then it would be cool to keep one in it with some modifcations to make it strong. But if your wanting to go with an engine that is famous on the tracks, since it replaced the 327, then go with the 350. I have an original 283 in my Impala and I intend to beef it up just so I can keep the original block in the old girl. To me it's not always about how much horsepower you got but how you use that horsepower. Kind of like the old saying, "It's not about the size of the the dog in the fight but the size of the fight in the dog."