Couple Questions

[Mastodon08]

Have a question about the valvetrain and also the transmission for a 70 B-body. Building a 440 bored .030 over and 906 heads, the cam's maximum lift is .513"...so wondering, what kind of rockers should I use? Also, for the manual A-833, what type of clutch master cylinder should be used? Any recommendations?

[Kern Dog]

I know it sounds boring but if the cam is a hydraulic, stick with the stock stamped steel rocker arms. I only switched to the aluminum adjustables when I switched to a solid lifter cam.

[Mastodon08]

Nah, sounds about right, I read something earlier about that...the difference between using hydraulic and solid lifters. You think these rocker arms from summit will do? https://www.summitracing.com/parts/mel-mr-850/overview/make/chrysler

My only concern was the .513 lift.

[Challenger340]

I would be more concerned with correct Piston selection, rocker arms can be changed later ? Pistons not so much !
Read the permalink in this section if you haven't heard about 440 Piston selection and educate yourself, mainly because some shops even to this day are still unknowingly using the motor home pistons

[c00nhunterjoe]

And were the heads clearanced for the extra lift?

[Mastodon08]

Yes the block and most of the parts were machined by a professional shop by a guy who was an expert with Mopar stuff. There are valve reliefs and the 906 heads had just a little metal taken off the bottom. I told the guys what I was going to be running for a cam, so it should be good to go.

[c00nhunterjoe]

Yes the block and most of the parts were machined by a professional shop by a guy who was an expert with Mopar stuff. There are valve reliefs and the 906 heads had just a little metal taken off the bottom. I told the guys what I was going to be running for a cam, so it should be good to go.

Not to question, but we hear those exact words alot, and it usually ends in dissapointment. Do you know what part number pistons went in it? And it the only thing done to the heads was "a little off the bottom" you will have issues

[69wannabe]

The valve guides have to be machined down or the retainers will bottom out on the top of the valve guide. a 513 lift may be borderline on this with a hydraulic camshaft  so it may or may not work ok. I had a 510 lift cam running the 346 cast iron heads and they worked fine, I have always heard anything over 510 lift and it would bottom the retainers out on the guide. I am running prepped stealth heads now so no worries now but I knew I was close with the cast iron heads.

[Mastodon08]

I'm definitely not using motor home pistons lol. I went with speed pro, and trust me the guy at the shop is really a pro. I've seen his whole shop and they work on every type of engine in that place. He also had an almost flawless Superbee with a 383 with 906 heads also. I will obviously check the valve to piston clearance with the old play dough method before I start this thing up. As far as the retainers hitting the guides, I measured with the retainer on the valve stem with keepers in and the distance from the bottom of the retainer to the guide was a little over .700", so there should be enough space.

[c00nhunterjoe]

Speed pro makes junk pistons too that are advertised incorrectly online. Do you have the pn? Most likely they used the 2355 flat top with reliefs. If so, you are low compression.....

[c00nhunterjoe]

Even the 2295 domed pistons with 906 heads and felpro gaskets are not high compression. Sorry to be the bearer of bad news here .

More important question is if this professional shop that are experts in everything is building it, why are you not using the rockers they said to use?

[Mastodon08]

Dude seriously just get off of here stop being a smart ass and dissing everything about what I'm saying; I came on here to get advice and clarity on a project not to deal with this crap.  Speed pro pistons are not junk and there's plenty of people online who will say that they are great pistons and have lasted for them and taken a beating, and my compression is going to be right around 10:1 which is just fine for what I'm building, and if I remember correctly, the shop said the old style rockers or adjustables were okay, but I wanted to see other opinions and I couldn't quite remember what the guy said because it's been a long time since I dealt with that shop and this project has been sitting a while.

[c00nhunterjoe]

Im not dissing anyone. You are asking for clarity, yet are getting pissed off when you are getting it. How is that my fault? You stated they are speed pro pistons with valve reliefs. That will be the 2355 pistons with a 2.061 compression height. Not terrible compared to some other brands but not 10:1 by any means. Dont get shitty with me. Do the math for yourself. 

Im not the only one that has asked for clarification on the pistons. It is a crucial part of the build and critical before "advice" can be given moving forward. Do you know the rest of the specs on the cam? Do you have flow numbers and cc numbers on the heads? Do you know what head gasket was used? Lots of questions that every engine builder on this site will all ask before giving you advise or clarification. We have to know what you have.

[c00nhunterjoe]

If i came across as harsh, i apologize,  sometimes it is hard to read a person via text on a forum. We are all on here to help each other.

[Nacho-RT74]

If you are thinking on Speed pro pistons is because you are maybe on a tight budget? Check Keith Black hypereutectic pistons. With just 25-30% more investment will be on way better numbers for compression rate.

Note: there are better prices for KB than summit, jegs or whatever known seller. Check the web site just to check specs, make your selection and google the PN.

Nobody is saying Speed Pro pistons are really a junk by quality, but just that THEY DON'T GET the correct compression height for a nice performance engine. Certainlly not the one you are pointing out. In fact, maybe some of the KB pistons available won't get the 10:1 CR without decking the block, since their specs posted are based on a correctly decked block, and correct chambers volume ( and stock parts are usually way far away from those numbers )

[c00nhunterjoe]

And again, speed pro are not junk. Assuming it has 2355s in it, they are an ok moderate budget choice. Just not a 10:1 choice.  But looking back, this is your same questions since 2017. What have you actually purchased or accuired so far?

[Challenger340]

The most common speed pro pistons are the L2266... L2355... and L2295.  

With any of the open chamber 906/452/346 etc., cast iron heads ?
only the L2355 really provides a suitable mid 9's CR using a composition style Head Gasket for mild cam/street builds ?
with,
the L2295 typically in the low 10.2 to 10.3 range and can be subject to careful Cam/Fuel selection as prone to detonation on the HUGE quench distance.

I know of no considerations that would prompt an engine professional to select either the L2266 or the L2295 as their first choice for most open chamber Cast Iron head Builds ?
Just my opinion here....
but only the L2355 is a viable choice ?

[BSB67]

If i came across as harsh,

Maybe just a little........Stop that, Kettle