350 piston ht.

[panhead59]

1989 .030 over 350 ci. engine. Can anybody tell me the measurement from piston top to block deck. I'm just checking to make sure it hasn't been decked. Thanks. And a special thanks to ALL our Vets out there on this Memorial Day weekend, especially to those that "gave all" !!!! SEMPER FI

[Warrens69GMC]

Since its not stock you need to figure what pistons you have and their compression height. Centerline from the crank to deck height is 9.025

350 aftermarket pistons vary widely, and can change:

345np030 - 1.54 compression height
H859cp030-1.435 compression height

.105 difference!!

[Marv D]

Take a look at the ID pad on the front passengers side of the block deck. IF all of the numbers are perfectly visible, it's probably not been decked. If the numbers are gone, or almost gone,, it;s been decked. How much???,, only a COMPETENT machinist will be able to really tell, Not just everyone has the proper tools to measure it correctly. The too,, not just everyone with the proper tools knows how to use them 'correctly'.

[panhead59]

Numbers look untouched. Deep and clear. V0301TPB TKJ510960. Pistons are new and are punched .030 but that's it. No manufacture name or symbols present. I bought this long block already rebuilt, so the pan is installed. I know that's not a perfect scenario but I got the engine, a posi rearend, and a "core" th350 trans for $1,000 so I couldn't pass it up!!! I just pulled one head to make sure I hadn't been taken for a ride ( and cyl. walls not rusted from sitting), and it has been rebuilt. Never fired as advertised. Shiny new pistons, clean as a whistle. I really just want/need to know if I should just reinstall the head and run it like that or if I can get some more power out of it with something simple and inexpensive like a cam change. I just don't want to have a "dog" running engine. I've got a new cam in "the stash", I think it's just an "RV" cam. I'm just brainstorming this engine right now. What would u do? Just looking for a stout sunday driver w/out a big budget (thinking alum heads). I know-dream on!!!

[Marv D]

Easy to measure deck clearance on an assembled motor, I misunderstood what stage fo the build you were at. Bridge the bore with a good straight-edge and measure clearance from top of piston to bridge with feeler gauges. Easy-peasy

Measure at the piston PIN centerline so piston rock doesn't influence the measurement. The balancer "0" mark is probably close enough for TDC unless you suspect it has slipped. If you have a mag-mount dial indicator no better time to check the timing tab really IS 0

[panhead59]

OK good. That's the way I did it on my 455 Pontiac. Anyway, I get about .110". It's pretty hard to stay steady and square but that is about as close as I can get. What do u think? See top post. Flat top pistons by the way.