lillee64

ok i have two engines, 1 is an 84 305 and the other is a 85 350. one of these will be going into my 90 iroc z. its a manual 700r. i want to upgrade to ported vortec heads, stroked, new cam, stuff like that eventually but i think newer 305 produce more hp than the older 350, plus both of these are truck engines so dont they have lower compression? what to do?

Doom86

What heads are on both motors?

lillee64

both are stock

Doom86

Casting numbers tell you what heads they are. Most heads are stock and not all stock heads are the same.

If you don't intend to build the motor before putting it into the car then I would put the 305 in the car and put the 350 on the engine stand and start tearing it down for the vortec build.

lillee64

i was thinking about putting in the 350 and selling the 305, i was gonna buy all my rebuild stuff part by part and just put it all together down the road

1ADan

iTrader: (4)

its not gonna be easy to sell a 305; I gave mine away just to have some more room in my workspace. its much easier to take your time building up a motor if its not installed in your daily driver. what do you have for an engine now? is there anything wrong with it?

lillee64

id have no problem selling my 305 for about $300 in my area, i kno the 350 is the better engine in the long run but is a 85 350 worth it? or should i get a newer one to build?

Doom86

I'm with 1ADAN on this one good luck selling that 305.

If you can sell them easily do so and get a 87+ 350. If you plan to invest a good amount of money into the thing you may as well get a good base. There are a lot of good reasons to go roller. I have a torn down 4 bolt main 350 flat tappet block sitting in the back of my truck waiting for a trip to the scrapper just for that reason.

lillee64

well most likely since i will be buying basically every part inside i might just buy another block too

CanuckBird

350 all day long....

lillee64

ok i just got a 92 350 today, all taken apart though. what would be the best way to put it back together? and i want decent tq

Doom86

What heads did it come with?

lillee64

id have to look them up, i want to go vortec though

lillee64

ok the block casting on my 350 is 10054727 and the heads are 14102185