305-350 swap

[bitchin85]

Could be wrong but I thoughtit was onlyvertecs that had the bolt holes at adiferent angle.. Anyways swirlports do suck.. It would be worth it to pick up a rebuilt set of camelhumps or something along those lines..

[MR .T]

vortec heads have a different angle where the manifold and heads meet. i think the runners are angles differently also.

[bitchin85]

pretty sure the heads are the same angle, just the bolts are at a diferent angle.. and they only u 8 bolts instead of 12

[Jonboy]

The center 4 bolts (2 on each side) have a different angle, I think it started on the TBI engines, or with the centerbolt valve covers (pretty much the same time). You can oblong the holes with a drill bit to make it work.

[bitchin85]

pretty sure vortecs are on their own from any other head.. your right about the centerbolts but on vortecs, they dont even have the center four bolts and the outside 8 go straight down into the head

[Jim85IROC]

Clarification:

Vortecs, as mentioned, are a completely different animal intake-wise from the old stuff. 8 bolts instead of 12, and in different locations.

Within the old "normal" style, there were 2 different intake bolt setups, the "early" and the "late". The "late" put the 4 inner bolts at a different angle (but same physical location) than the early ones. As mentioned, this started with the centerbolt heads in mid 86 to 87 depending on vehicle & engine. With Corvettes, though they went to centerbolt heads in mid 86, they retained the "old" manifold bolt angle throughout their smallblock run through 91. With f-bodies, they went to the "new" bolt angle starting in 87 with the centerbolt heads, and I suspect that the trucks were the same way.

I've seen companies (Holley come to mind) offer angled shims that allow you to elongate the bolt holes in old intake manifolds to work with newer heads. But, new intakes are cheap ($100 range) and if you're going to toss that motor in anyway, you might as well spend the money for a new intake and a can of engine paint so that your motor will look brand new when you put it in.

Hopefully that didn't further confuse the issue.

[85silverbeast]

I got the 350 in there me and my friend knocked it out in two days and my old intake did fit with a little modification to the two center bolts they are in the same location but the angle in the new block is different. The block was pretty clean it looked good when we took off the heads. I just replaced the valve stem bushings with rubber ones instead of those hard plastic ones which burn and crack right away got a head gasket kit and that was it. By the way the block was a vortec.The manual fuel pump did work the holes for it were just covered with a cover with screws on the 350.