engins questions. NEED HELP!!!!

[94ss68c10]

i have a 350 block casting number 3970010 , its the highperformance block , 4-bolt main, and i just realized that the heads that came on it are different and the combustion chambers are different so im not gonna use them but i have a nice set of 305 heads casting number 14014416 , which are the 305 HO heads 58cc, 1.84-1.5 valves . . i have a rough calculation of 10.8:1 compression with these heads. will this be too high for pump gas, say 93 octane? any replies will be greatly aprreciated

thanks, Levi

[Boost Addict]

Don't put 305 heads on a 350. While you may have added compression, those heads won't flow at all.

[lozanoa11]

yes you can run pump gas on that but Like Rick said they may not flow how you want

[81DaytonaPaceCar]

x3...avoid 305 heads...

[Orange Terror]

I did that once when I didn't know better, it took the rings out of my motor after a few months and didn't really run better before that.

[94ss68c10]

the crappy thing is is i dont have anymoney for heads right now. when i bought this motor it was complete and supposidly ran before that but how could it run good with one head haveing 74cc chambers and the other side haveing 64cc chambers??? so i guess i should have asked is will it run alright with the 305 heads cuz i just want it to drive for now. i mostlikely wont have money for heads cuz my girlfriend is prego and i was building this motor for my truck to sell for money for the baby.

[94ss68c10]

ok here is my question... would i be better off using my 72 vette block with my 305 HO heads or better off with my 305 block with heads?

[chevyman9306]

the crappy thing is is i dont have anymoney for heads right now. when i bought this motor it was complete and supposidly ran before that but how could it run good with one head haveing 74cc chambers and the other side haveing 64cc chambers???

Are you suggesting that you have 2 different heads on it??? If you do thats not good...plus if its the project park it and pull the heads...sell them and then wait till you can add the money to buy heads for it...trust me I know it sucks to park it but I had to park my t/a for a month and a half cause 2 weeks after I bought it the electrical went out...sometime you gotta do what you gotta do to get it right

[81DaytonaPaceCar]

ok here is my question... would i be better off using my 72 vette block with my 305 HO heads or better off with my 305 block with heads?

Just to clarify, the 72 vette block was likely used across a variety of platforms...just being from a vette doesn't necessarily make is special.

Second, it would definitely be better to use the 305 block with the 305 heads...

[Plantfoam]

At the very least, many of us have leftover 350 heads (like myself) from rebuilds....If you had some that were even stock, then that would be much better than 305 heads. Sure, you get higher compression with 'em, but it's a 'cheap trick', and you will end up with a non-breathing engine (aka: valve shroud).

[LS1Formulation]

You can buy a pair of 64CC Vortec heads (which are the highest flowing production small block heads EVER) for about $200-$250 used complete. They will add about 30-40HP over any smog era heads. You do have to buy a Vortec specific intake, but it's well worth it to install these heads. Don't even mess with any pre-vortec production heads. Not even worth the time or effort.

[Merlin]

Will it work yes your engine will run and yes it will be ok on pump gas. Do I recomend it tho no way if you can avoid doing it. I had a friend of mine with a 84 cutlass do the same thing had a good 4 bolt main block with all scat foraged internals in it. Didn't have money for heads so he put the old 305 heads he had on. His was running about the same compression it worked but they hurt the cars performance realy bad. It ran ok at best they just didn't have the flow needed to keep up. Wait till you can afford the 350 heads or use the 305 block and heads.

On another note I have had alot of problems personaly warping 305 heads on every 305 I have ever owned I personaly hate that engine I think it was one of GM's worst ideas ever. Twice in my 1500 chevy. Once in a 83 monte carlo then after I changed out the head the motor put a rod through the side of the block about 30xxx miles later.

My uncle has had them go bad 4 or 5 times in his plow truck. He does beat the crap out of the truck but nothing that a good 350 could handel. Going to be putting a 454 in it here soon.

[.DetroitKing.]

305 heads suck ass.. please don't use them.
if you are on a budget the vortec cylinder heads are an amazing set of heads you can get for a VERY NICE price out of a summit catalog for that 350.

[94ss68c10]

ok im saving the 350 block till i have the budget to work on it and the 305 will go back in the truck for the time being(cuz i miss driving it)