Unreal

I think you need the rocker stands to run the stock rockers.

I would do inconel. No need to mill them more if you are boosted. Retainers depend on cam/springs/etc.

croatbob

ok spoke to the lads at mast. they recommended

mast 305s with the below upgardes
inconnel ext valves
hollow steel int valves
ti retainers
comp triunion upgrade

Unreal

And what redline/cam? SS intake are fine if you want to rev to 6200.

croatbob

Boosted 427ci. No need to rev the *** out of it considering its nor a track or drag car purely Streeter. Factory redline I'd say. Even more so on stock slugs

Unreal

Factory is setup for ti intake so that is why I'm concerned. You better check into it. You don't see ls3s revving to 7200

croatbob

Yep spoke to the tech dept at mast, tech dept at a resellers n both assured me the ti intake in an overkill unless I'm building a high revving huge cammed n/a stroker. Hence why the standard mast 305s are offered in stainless as the platform n ti as the extreme

Sleeper09

I had WCCH then switched to Mast. Race Proven and I believe we ran into some valve float with the WCCH heads on a turbo build. I do not think the Manley valve springs that WCCH installed had enough seat pressure for my application. The springs on my Mast heads have just over 180 lbs of seat pressure if my memory is correct. Also if you are going to use your stock rocker arms you will need longer rocker arm bolts. Just a suggestion, set your heads up from the start to handle more boost later along with the 7k rpm when you do the bottom end. I went with the ti intake because I did not want to chance valve float with these big intake valves.

croatbob

yeah i spoke to taylor at dallas performance aswell and they have done builds there making 1300whp on stock s/s valves used in mast 305 head package so im confident the hallow steem is a step in the right direction without the cost of the titaniums. mast heads are being ordered next week so i got a top end that will suit a good end build for 1000whp.

yur2slo

I'm using the Mast 305's on my ERL 6 bolt build - using the ss valves as well. From all the info I gathered the titaniums are more necessary on high rpm's (8k +) that Ill never hit. Picked up some shaft rockers too.

croatbob

Yup getn the same response from all the builders n techs. Unless ur building a n/a high rev engine there's no need. I think ppl are assuming cause they are stock ti they need to be running ti aftermarket. Ti will make them more valve spring friendly but the extra 1k for the upgrade just don't make sense.

lane_change

Bringing this back up from the depths for some more questions and insight...

My build has:

RHS Race Block-4.165 Bore Standard Deck
Callies 4.100 58X LS7 Crankshaft
Callies Rods
Diamond Pistons/Rings- Coated Skirts (-4cc)
Calico Coated Main/Rod Bearings
Machine work/Assembly of shortblock by Proline Race Engines
Katech C5R Timing Chain for RHS block
248/262 111 LSA Cam
Lunati Linkbar Lifters
WCCH Stage II 51cc High Compression Heads (E85 car)
ARP Head Studs
ID 1000 Injectors
Wilson Sheet Metal Intake Manifold for Direct Port Nitrous
2" ARH Header w/ ORX
Akrapovic Exhaust
RPS BC2 Clutch
etc...

I just brought this car here (Houston) from Denver, where it made 620/575 SAE, but now at sea level with these heads it calculates that my static compression is ~14.8:1 which is quite high, even for an E85 car. So I am thinking to switch heads and put on a 6 bolt head with a larger chamber size. I have debated going with forced induction (blower/turbo), but the motor was built for nitrous and even with a 70cc head I can't get below a 11.7:1 compression unless I run a thicker head gasket which I'm not sure exists for a 4.165 bore from Cometic or anyone else. So if I am forced to stay on the bottle, then higher compression is okay....not 14.8:1, but 13:1 or so would be fine. My million dollar question is, which heads?

Mast 305cc
RHS 291cc
PRC 285cc
other?

My main concern is performance vs. budget. A $1000 difference here isn't a big deal, but I know some do the PRC285cc heads w/ Ti valves for around $3000-3200. The Mast 305cc heads w/ Ti valves are around $4500 I believe?? Not sure on the RHS heads to be honest. I know Brodix, All Pro, and others make great setups as well, but now we are getting into the $6k range and I'm not in love with those ideas if I can help it. Number wise, I'll be looking to be in the ~650whp n/a range if possible and then probably just run a smaller 200 shot on the car for now so maybe looking at numbers in the 830-870whp range or so.

lane_change

Bumping this back up since I have my WCCH Stage II heads for sale so I am trying to figure out which path to choose.

MAST 305cc 68cc? 11.8:1 compression ratio based on my calculation w/ my current setup

or

ALL PRO 12-4 54cc? 14:1 compression ratio based on my calculation w/ my current setup

Not sure if anyone sells a slightly thicker than stock (.051) head gasket for a 4.165 bore LS7. RHS sells a .036, but that would throw the MAST 305cc's up to around 12.3:1 and put the ALL PRO's up to 14:6:1. So unless I can find a thicker gasket, I think the ALL PRO's may be a bit too small chamber size for my application and I don't feel like changing pistons right now.

BOO666

If you want to set records go with what pro line built for Keith Berry run mast . Keith berry has the worlds fastest ls period . If you are running on the street run prc

croatbob

my mast 305s ended up 3700 delivered. speak to some dealers as they offer better prices then mast themselves

lane_change

You opted to go without the Ti Intake Valves though correct?

I would have to have someone much smarter than myself tell me why that would be worth doing. Since my car is an N/A car with a bit higher rev limit plus nitrous, I would think that going Ti would be the better decision long term for the success of the build. Maybe I'm wrong, but I don't think the $800 difference in Ti vs. SS is really a deal breaker, so whatever's better is better. Feel free to chime in if anyone knows better.

croatbob

aspirated your prob going to see 7000rpm. mines boosted and has my shift light set at 6300rpm. spoke to redline n dp and both said the 800 wud be better spent elsewhere. you dont need to rev the *** out of boosted cars

lane_change

Yea, I understand the use of SS if you have no intention to rev very high due to the powerband, but I think for my application using a lighter material will help increase peak rpm efficiency and reliability. Less stress on the valvetrain components lifting a lighter material. I have a call into a Mike at Presence Distribution regarding a quote for some MAST 305's right now.

lane_change

I have decided to just go with the MAST 305cc heads. New questions:

- Will it be necessary or recommended to have these new heads sent out for port work cleanup or anything upon arrival? I am debating having someone like Greg Good or someone similar work them over if they need some tweaking for optimization.

- Should I go with inconel exhaust valves or stick with SS? This is currently a nitrous car so I understand that inconel is mostly for boosted applications with higher EGT's, but I am still debating changing to a boosted application in the future and trying to decide if I should pay for the inconel at this time or save the money and cross that bridge when I get there assuming I ever do go boosted in the future?

backchannel

With Mast heads, you may have to mill top of intake manifold runners as Mast intake side may not be machined flat high enough. I ran into that.

THE BLACKBIRD

I'd get the inconel, it would help either way. Its always a good idea to get your heads looked at, but its not necessary.