Difference between 85 n/a vs a 109 block?

[getchasum]

I found an 85 n/a 3.8 forsale for a great price and I'm looking at it for a spare block and parts. I'm wanting to know all the differences between the 85 and a 86/87 turbo block.

* Does the 85 have a place for the knock sensor?
* If it don't can you tap it for a knock sensor?
* Would it have the 8445 heads?
* Does it have the same rods?
* How is the casting of 85 block vs a 109?
* Is it considered a 109?

Any and all info you can give me is greatly welcomed. I figured some of you guys may have use one of these blocks

Thanks,

 

[cool 84]

There are lots of rumors going around with little facts to back them up. People will say the hotairs are weaker, blah blah blah.

As for strength, I talked to Duttweiler and what I got out of it is if you're going to push it to the limit like 9.90s on a stock block you're best off going with the 109. Anything short of that the early block will do just fine.

The valley area is ugly compared to a 109, you'll want to take a grinder and smooth the casting somewhat.

The deck is taller so you will want to run the hotair steel shim headgaskets which are better than the IC gaskets anyway and cost less than $10 a piece.

The knock sensor hole is there already even on the NA ones.

The crank (if turbo), rods, and heads are the same.

Head bolts are different. The threads come right up to the deck surface and some think that head studs are more important on this block than the 109 to prevent cracking. I agree if you plan on pushing it.

You will have to drill a hole and tap it for your turbo oil return line since ours goes into the intake manifold. It's easy to do.

Hope I covered everything.