85 Chevy P/U – engine tear down

This post highlights the engine tear down of the old 305 in my 1985 Chevy Short-Box, Step-Side Restoration Project, in preparation for rebuilding.

This is really going to be more of a “show and tell” post… the pictures pretty much explain it.

Here’s the engine after it was removed.

85pu_engine_teardown_01 85pu_engine_teardown_02

The brackets, sensors and accessories were the first to go… then the exhaust manifolds were removed. As you can see in the picture (sorry for the quality of this one), the two “shiny” spots are broken bolts in the drivers side manifold… bummer. I could not get the manifold to budge — the bolts were frozen/welded to the manifold! Arg! It took a bit with a drill bit down the center of the bolts to get the manifold off, and then a little heat on the bolts to remove the broken studs from the heads — no biggie.


Next to come off were the rocker covers — everything looked good under there.


Then the intake manifold.


The rocker arms were loosened off and the push rods were removed.


The heads were removed next.


Down to the block, I removed the timing chain cover…


Flipped her over and removed the oil pan.


Here you can see the crankshaft after the oil pump and pistons have been removed.


And finally… a stripped down block. The timing gears and chain, camshaft, crankshaft, main bearings, oil filter port and flywheel have all been removed.


Other than that, I cleaned up the block a little, removed the old gaskets and all bolts and it was ready to be sent out for testing and machining. The heads went at the same time, after I cleaned them up.

Stay tuned for the rebuild! :)

Links to other parts in the series;

4 comments on “85 Chevy P/U – engine tear down

  1. the only thing that might be different is the flywheel used. Older 4.3 engines are externally balanced on the flywheel,so you may need the 305 flywheel to lessen vibration and extend engine/tranny life.

    Kyle’s reply;

    Thanks for the info, Dennis!


  2. That’s an interesting tutorial, obviously I am still a beginner and I have a lot more to learn about engines. I think I can handle the tearing down, I am more concerned about rebuilding. Do you have any experience with Chevrolet engines?

    Kyle’s reply;

    You’re really a beginner, eh? That IS a Chevy engine — a 305 to be exact. 😉

    Here’s the rebuild.

  3. I have a 1986 step side with a 4.3 v6. The engine has a knock and I have purchased a 81 full size chev sedan with a good 305 to replace the v6. I am not sure but I think the only difference other than the exhaust etc. will be using the rad and fan shroud out of the sedan.I am watching your column with much interest as I would like to change engines myself but it has been many years since I did any mechanical work like this. Keep up the good work as it looks very interesting.

  4. Hi Ed;

    I have never done a V6 to V8 swap, so I can’t answer your questions from experience. However, I have talked with a couple of guys that I use to reference (they know their stuff most of the time!) and none of them think you’ll have to change much.

    The fan sizes shouldn’t be a problem (even if the V8 is slightly larger, there is plenty of room inside the shroud… you could probably unbolt the shroud while you mount the clutch fan and then bolt on the shroud… heck, you don’t really even NEED a shroud… it’s just there to stop you from stickin’ your hands in there!), and there should be no problem using the existing rad in the PU.

    The bellhousing pattern should be the same, but you may want to double check the flywheel (compare it to the V6). I’d check the starter (although it should fit, I don’t know about the cranking power of it), along with the alternator for the same reason.

    Other than that, all I can think of would be the exhaust manifolds (as you pointed out) and the motor mounts. From there, it should just be a matter of getting the sensors hooked up and away you go! In theory, of course! 😉

    Have fun with your project! If you take any pics and feel like sending them to me, I’ll be glad to post them — just contact me and I’ll get you my email address.


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