are the pistons Flat tops or Dished.
Please say Dished

 

dished

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"So many Mustangs, so little time..."
ICON Motorsports

 

All of them? Regardless of year?

I haven't taken mine apart to check, but I was lead to believe the later years used flat tops. From the reaction to advancing the timing over factory, it wouldn't surprise me that mine are flat (6 degrees produced lots of pinging, requiring midgrade to correct).

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, WP 305 heads ported & polished, TBD headers & hi-flow cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

All three 86 lg4 motors i've had appart had flattop 4 valve releif pistons, with the compression ratio of around 9.5

The 82 Lg4 i had appart had dished pistons, and 8.6 compression

I belive they went to higher compression in 86.

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It's always SOMETHING
"Sounds like Barry White at idle, Teddy Pendegrass wide open..
if it don't sound like Micheal Bolton your alright"

 

That may help explain why the guy with the '84 Monte Carlo 305 HO is so frustrated that I'm a good 1/2 second faster in the quarter than he...

[This message has been edited by five7kid (edited January 26, 2001).]

 

I have an 82 firebird w/ an lg4, i know the compression is sh***y so what kind of pistons would you recommend?

 

Some of that compression difference is probably in the chamber volume.

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Later,
Vader
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"Keep rollin' rollin' rollin' rollin'..."
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KaleCo Auto Parts

 

Domed, no doubt. They're usually called high compression pistons. The only problem is that they are almost impossible to find for a 305. If you find a dealer that can get some, let me know the address!