350 chevy compression/performance question

I have a 66 Impala SS ragtop with a small block chevy 350 and Turbo 350 auto tranny. I just like to drive it around now and then and go to a show. My motor is making some very odd noise that we now believe to be in the bottom end. The few who have listened to it have not had a solid guess. The last guess was "maybe it is a wrist pin" Sounds like the lifters do not quite oil up. The noise is present when I let off the gas and the rpm's start to decrease.

I have replaced the cam/lifters/valve springs/push rods and rocker arms but the noise is still present so that is why I now believe it is bottom end.

A local shop wants $825 to completely re-do my short block. Due to the wifes '67 Camaro taking up our money right now, $825 is a bit steep at this time.

A guy I work with has a 350 with approx 5,000 miles on it that he will sell me for $400. The issue about this motor is he stated "it just has some low compression pistons in it so you can run any gas without ping"

So,,, if I just want a short block that is known to have no issues but has some lower compression pistons (no idea what compression exactly) for a decent price do I buy that or do I really need to wait until I can specify the pistons for a higher compression?

My current pistons are just some flat tops that I have no idea what the compression rating would be.

My cam is a new comp cams 12-242-2 int exh adv duration 268 280 dur @ .050 224 230 valve lift .477 .480 lobe seperation 110 the heads are the old style camel hump heads that were gone thru a few years back. my intake is your basic Edelbrock Performer RPM

So, I will listen to anyones input on the "buy the unknown low compression motor for $400" or "wait til you can specify your compression"

If I do buy the $400 motor, my new cam, lifters, valve springs, intake, heads will all go onto that bottom end.

I want to get this noise issue resolved so I can have my 40 series flowmaster mufflers finally put on.

Thanks Much.

rick2950 at hotmail

Reply to
Rick2950
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I wouldnt buy the other block without a compresison test. For all we know your describing a transmission problem.

Reply to
ed

I'd go straight to the tranny-to-block bolts & ensure they have not worked loose. When they do, they make some weird noises--from lifter-like to main-bearing sound-alikes. HTH & good luck, S

Reply to
sdlomi2

Also check the flex plate for cracks. It also makes some strange noises that are often misdiagnosed

Reply to
Bob La Rocca

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