can you throw 305 heads on a 350 bored to 383 and if so would it produce enough horsepower to be worth the time

 

not worth it. If your building a 383 just get some decent heads.

 

absolutely not
305 heads barely flow well enough for a 305, and are very flow challenged on a 350... on a 383, it would be terrible

 

Bigger engines need more air to make HP. Not all castings are the same and there are a few good 305 head castings. They're good for bumping up compression but if they can't flow enough air into the engine to make power, higher compression is useless.

Aluminum heads have become very affordable. Buy some good aluminum heads and you can feed the bigger engine plus reduce a bunch of weight. If aluminum heads are not in your budget, a set of 350 Vortec heads will be much better than 305 heads.

 

For the record, you can't bore a 350 to 383. You have to increase the stroke and bore 0.030" over (unless you do like GMP and use a 3.80" stroke & 4.000" bore).

The LG4/L69/LB9 305 heads with 1.94" intake and 1.50" exhaust valves will flow as well as L98 350 heads. With decent port/bowl clean-up and 1.60" exhaust valves, they'll flow even better. You can support a mild 383 that way.

But, by the time you did all that to 305 heads (especially if you paid somebody to do all the work), you're most of the way to decent aftermarket heads.

 

New to this forum, but for the record all you need for a 383 is to punch the 350 out .030" over, and put a MODIFIED 400 crank in. and VOILA!!! you have a 383

 

Which would be the stroke increase that five7 mentioned, but nobody uses modified 400 cranks anymore.

 

At $170 for a new stroker crank it would probably cost you that to turn down the journals on a 400 crank ( on top of the crank purchase price)

 

Plus to make an old school 383 with a 400 crank, you also need to use the 400's shorter rods to work with the 350 pistons. Now everybody uses the more common longer 350 rods with stroker pistons which locates the wrist pin higher.

 

The old school 383 also forces you to a 2pc rr seal and could get interesting in finding a standard flywheel.

 

Not really. They are readily available. Expensive, but readily available.

 

Thank you for correcting me. The last time I checked the machine shop I was going to use told me that but then again that was more than 5 yrs ago.