TheNewStyle

Guys I know I'll see a compression bump from adding 305 heads, but what are the pro's/con's of putting a set on my tpi for a few months?

Atilla the Fun

Depends on WHICH 305 heads. And we've discussed this about 26972 times, so search, and read other people's similar threads.

TheNewStyle

Well here is the deal, the heads are off an 86 14088551 sbc 305 block. But I can't find casting numbers on the heads anywhere? Anyone ran into this problem and have any idea what I should do? The engine I'm told came from a carbed 86 Iroc. And if I where to run these heads, do I need dished pistons? If you have a thread that shows this info, just show me a link.

racer7x

iTrader: (1)

I just completed this swap. 1985 58cc chamber heads with basic pocket porting, .032" head gasket, piston deck height .027" down on stock 1992 350 pickup shortblock and pistons = 9.71 compression.
Comp Cams 268H cam .454 lift, stock intake and Qjet carb, with exhaust manifold and no Cat, Dynomax 2.5" exhaust.
No detonation on 87 pump gas pulls good to 5000rpm. Pretty happy overall for a low dollar build.

Atilla the Fun

Those should be 416 heads. With dished pistons, they'll be fine.

TheNewStyle

I've got an 88 TPI L98 350. And the heads are off a 14088551 86 iroc 305 block. What have I got to do to just drop them in? I'd rather not deck the block if I don't have to. Even though I'm sure its a good thing to do. Will valves and pistons clear? I run 93 right now so that is easily handled

TheNewStyle

@attila, they will not work with factory L98 pistons then I assume?

Atilla the Fun

L98s came with dished pistons, stock. These 416s should bolt right on, with no problems. You'll still need to run premium unleaded. No need to deck the block. I suggest the GM 10105117 head gaskets. They're perfect for this, and you can get them for $15 each.

TheNewStyle

And this is why I love this forum. Thanks Atilla, looks like she's getting grounded for a long weekend to get 416 heads, headman headers and a custom y-pipe to mate to the borla 3" catback. A.I.R. will be nice to have gone!

TheNewStyle

Speaking of removing the air system, anybody have a part number for the new serpentine belt? I know it needs to b re-routed. And @attila, would I get the head gaskets from a dealership or napa?