Kepp your eyes open over the next two weeks as there is a chevy 305 in this years Challenge the first week of Oct.  

these were not the heads used on the motor. they used 64cc heads that were milled down to get 60cc chambers. they were vortec 350 replacements with 1.94/1.5 valves. there was no mention of checking valve clearance or notching the piston. the pistons in the motor were micro dished with 4 valve reliefs. i have built a similiar motor, except i am using stock 87-95 350 heads, and a summit cam with a 650 carter and performer rpm intake. 350's are great, but this article is an excellent source of inspiration for those of us who are building 305's for whatever reason. i have a 383 and and a 355, but i chose to build the 305 b/c it was my first build. also, several websites, such as chevycamaro.com, that list chevy head casting numbers have stock 305 heads listed that do indeed have a 1.94/1.5 valve setup.  

July 10, 2008:
Rayvinton, I'm sorry I don't know anything about the 305 build that engine masters did. I don't usually reply to posts either. I just read 'em to learn other peoples experiences so I can sometimes weigh out what I should or shouldn't do. But this is one post I gotta reply to.
I currently have a 1987 S10. 6 months ago it had a 406 cubic inch chevy V8. When gas prices started going above $3.00, I wanted a smaller engine with close to the power of my 400hp 406ci. So I stroked a 1985 305 to 336ci with a 3.75 crankshaft and a .040 overbore. Pistons are KB custom milled tops  with a slight dome to make 9.6:1 compression ratio. 5.7" rods.  I used 1978 stock 76cc chevy heads, port matched and polished, with 1.94 intake valves. I am using a comp cams 270H with 224 @.050 duration, .470 lift on both lobes. I used Crane Cams High Intensity variable duration lifters to make the cam approximately .440 lift/214 duration below 3000rpm. Custom ported/polished runners Edelbrock streetmaster single plane manifold, Edelbrock 600cfm with 1" 4 hole carb spacer. I HAVE NOT NOTCHED THE BLOCK TO CLEAR THE VALVES! there is no interference.... I tested as I built this engine, using modeling clay, with no head gaskets....No valve interference. (shrouding? it is so little as to not matter. This is a daily driven street vehicle, pooey on know it alls.) I tested before install-- 375hp at 5000rpm, at the crank, and gobs more of torque. Not to mention I get what I call acceptable gas mileage (18-19mpg)when I drive nice and keep it below 3000 rpm(aka 75mph)with the th350 tranny, 28inch rear tires, 3.73 rear end gears and variable lifters.(truck is level and lowered.) It's a good muscle engine, I don't care what anyone says a 305 is a good engine. Be creative. That's what hot rodding is all about. If I wanted to invest the money I could get 25 more horses, but I'm pleased with what I got. I'm NOT trying to win every race. Just have good muscle. It didn't cost much either. I got the block from craigslist for $50.00 in perfectly new rebuilt condition with a new .040 overbore. There is too much parts detail to list, but I got a good powrful engine for much less than the cost of rebuilding a 350 or a 383. get creative. Use the brains God gave you. 305's have the same mains and rod sizes as a 350. 2 bolt mains are plenty strong for 5500-6000rpm at reasonable horsepower levels. 3.75 cranks with 350 mains are inexpensive nowadays.  
there was very little clearance work to be done to fit the crank in the  block. Even without stroking you can do much more with a 305 than people realize.

I'm not even gonna pay attention to the skeptics this will draw. I shouldn't post in this thread? oh well. no where else to place it.  

To I_DONT_TRUST...
I agree with you. The 305 is just right in some caes and can be set up with some good power numbers while possibly offering better fuel economy on a long haul. It really boils down to doing what is best for your project and what you want from it when its finished (though I'm not sure their ever finshed, ehh...lol), while still staying as close to your budget as possible.
If your building it to sell eventually, go with a 350 because of the public sentiment. However, if your planning on keeping it awhile, you have a ready 305 block and want to save on a build, try your current block, build it, finish the project.... and drive it, enjoy it... knowing you completed it.
Always remember, the HOT ROD industry allows you to tailor your vehicle to you... your wants, needs and desires... as long as it does not interfere with the laws of our country.  

I recently built a .40 over 350 with Performer RPM upper-end. All aluminum heads and reached about 9:3:1. It is a monster for the money i invested.

However, The original 305 that cam factory in my 78 Malibu had well over 300,000 miles and i opted for the 350 for power. The 305 is currently being refurbished as a stock build + my .30 overbore. Small lopey cam and stock 305 rebuilt heads. Now, i have to say that i wish more people would be more enthusiastic about smaller displacement engines. Sometimes economy and power can be obtained within reason with the infamous 305. This engine will be replacing my 4.3 Vortec V6 in my 1990 C1500. I think its a great investment and hope others will follow! Thanks guys for the input. God Bless!!  

I find it funny, (weird), that the 305HO arrived with performance status when the 307 from yesteryear was deemed to be inappropriate for any high performance build-up.

The DART 305 heads have 1.94" intake valves with NO problems. The intake valve centerline is moved .060" closer to the exhaust valve. The production 305HO uses 1.84" intake valves.