305 heads good or bad?

83-z · #1 (**permalink**) 01-31-2006, 11:12 PM

i have 305 heads '87 rebuilt and need to know if they would go good on a '95 350 roller .10-.20 over? the specs i could find on them from mortec are: 14101081...87-95...305
14101083...87-up...350..........Gen.I, also used on crate motors, 285 or 300 hp, 64cc
chambers, 72' center manifold bolt
angles
not sure if they would be helpful or not. :}n

beast89 · #2 (**permalink**) 03-15-2006, 11:53 AM

to answer your question, the 305 heads would be a terrible idea without severe porting, which would greatly affect efficiency, you could port them out to giving the same amount of flow as a set of vortec heads but would vastly cut down on your fuel economy. my suggestion, buy new heads, vortecs from a 96-98 i believe 1500 would suffice well, check out some local boneyards and see what they have to offer.

Rare4thgens · #3 (**permalink**) 03-16-2006, 03:53 AM

305 heads are only good for an anchor or door stop other then raising compression. Vortecs are easy to get ahold of and so are camel-backs (202's). I would still hog em out though lol.

Got Rat · #4 (**permalink**) 03-17-2006, 03:52 PM

Vortec's would be alot better in the long run over the 305 heads.

You can find them at junkyards,sure,but in order to put a cam over .450 lift you have to grind down the back of the exhaust valve seat and machine them for bigger diameter z28-style valve springs. I had these on my 87 IROC...bought from a cylinder head company off of ebay already hopped up with the big springs on there up to .550 lift. I paid a little less than $1500 shipped to my door ready to bolt on.

greasemonkey · #5 (**permalink**) 03-19-2006, 03:00 PM

you could've gotten a set of AFR's shipped for that price...how did you spend nearly 1500 on a set of vortecs? scoggindickey has them with Z28 springs for .600" roller cam for $700 a set plus probably $100 shipping.
the stock 305 heads won't be good for a whole lot of lift either.

83-z, what do you want to put this engine in? what do you intend to use it for?

CamaroCliff · #6 (**permalink**) 04-14-2006, 08:42 PM

if they are stock 305 heads, the valves are tiny, and the springs are weak, and the ports are small. you will have great compression, but the valvetrain will take a beating, and you will be smoking before long. for the money to upgrade/machine them, youd be better off with 350 heads, or any aftermarket heads. i prefer Dart. their iron eagle series is affordable, and they are awesome.