Discussion in 'Small Block Tech' started by Reidk, Nov 16, 2020.
Those look low compression to me.
On the SP3, on my build, I noticed very very little if any loss of low end torque with the SP3 VS a dual plane.
That's good to hear about the intake. What cam are you running? And do you have stock pistons? Are you running a stock converter?
Top pic is a true low compression piston. Bottom pics are
mine. Am I being too optimistic to think that mine aren't dished quite as much?
Cam is a TA roller
Measured 11.1 to 1 compression, forged Auto Tec pistons.
9.5" JW convertor, stalls @ 3000, flashes to 3500, drives like a stocker.
Might have to cc them. Check part number. 1231899 it looks like on my 71 pistonsthey don’t look as dished as the 71 but definitely not a hi compression
Did you find steel shim head gaskets when you removed the heads?
I dont plan to pull my pistons. How much should I mill off the heads to be close to 9 to 1?
bout .030 should give a 50 cc head ,with the .024 head gasket nets about 9.03
Alec suggests taking.030 off the heads to get me close to 9.03. My cam specs 9:1 heads will be in the shop this week.
my motor is a 72 350. custom JE pistons with 9.5:1 compression. heads ported and polished. stock exhaust manifolds. Quadrajet carb set up by Ken at Everyday Performance. TA 284 cam 475"-223'/.475"-230',110'. 2800 stall converter from Jim, TA stage 1 dual plane aluminum intake. Letric Limited points eliminator, posi 2:93 out of a 69 GS. Sounds great at Idle, just enough lump. runs great. running through the same exhaust as I had on the stock low compression 2 barrel motor but sounds completely different. I would like to step up to a 3:42 rear gear, she would be a rocket off the line.
Cams respond to more compression. That's all you can do without opening up bottom end & ordering custom forged pistons
I'll be running the same cam but I have large tube headers and a single plane intake.
My pistons are #1231899
Yes I would mill the heads 30 thou and use shorter pushrods
Will I really need shorter pushrods?
Hit or miss on the pushrod. You may or may not.hard to say since you already had the thin head gasket.