timing on 350 with 305 heads
 

My carb and distributor are computer controlled.
Should I just time the engine with what the sticker says on my hood and let the computer take care of the rest or should I bump it down a couple degrees since the compression's a little higher than stock?

Re: timing on 350 with 305 heads
 

Compression is gonna be higher so I'd maybe look at bumping it down alittle for now and see how it likes it. IF you had datalogging equipment you can monitor for knock counts or spark retard. You can also add premium 93 gas to be safer.

Re: timing on 350 with 305 heads
 

Is there any advantage in running 305 heads on a 350?

Re: timing on 350 with 305 heads
 

not really. You get a bump in compression (up to ~10:1, but then you get smaller valves for less top end. A better bet would be aluminum L98 heads or vortecs.

Re: timing on 350 with 305 heads
 

You can find World S/R Torquer 305 heads with the 1.94/1.50" valves and 170cc Intake runners and good exhaust ports...
with a max lift of .560"! You won't get that out of a stock head...
http://www.summitracing.com/parts/WRL-042650-1/

I had a pair that I was gonna throw on my 350 (once upon a time)
But I decided to spend the extra $$$ and went with the AFR's instead...
I don't think that you can go wrong... especially if you have them already!

or do you have stock 305 heads...?

Re: timing on 350 with 305 heads
 

If you are running the stock comuputer controlled distributor, there is no adjustment in timing that you can make. The stock setting is not going to hurt the engine. The compression ratio depends on size of the combustion chambers, type of pistons, decking of the block and thickness of the head gaskets used. Some 305s had 58cc chambers, while others used 60cc chambers. So depending on the combination, you may be at 9.5:1 or 10:1 or something else. The stock 305 L69 (G) engines were 9.5:1 compression and ran fine on 91 octane. You will see a bit more power with the 350 lower end, but you won't get full advantage of it until you put on 350 heads with larger valves.

Re: timing on 350 with 305 heads
 

You can still set base timing lower than stock which will affect timing across the board.

Re: timing on 350 with 305 heads
 

I know using 305 heads on a 350 isn't the smartest move but it's all I had and this whole project is pretty much just about learning and not spending a ton of money because I didn't want to ruin any nice parts lol. Next time I'll just get a new crate 350 and drop it in, much easier.

More on the 305 head thing: I read that it increases a little bit of low end torque but craps out on you at like 4500 rpm. (I guess it makes sense because of the higher compression/smaller valves part).

Re: timing on 350 with 305 heads
 

Depends on what 350 heads you're comparing it to. They have smaller chambers and arguably better ports than the '70s smog heads. They have more meat to port, and when done up, can be a very competitive head. I run 416 305 castings on my 350.

Re: timing on 350 with 305 heads
 

I run the very same 416 cast heads on my 350 & man do I love it. With a decent cam youll be very impressed. It even ripped my "bullet proof" 700r4 to shreads. Because of that Im using my tax money to get a bowtie overdrive stage 3 700r4.