plasmeh

iTrader: (10)

I'm considering swapping my heads on my 350 + .060 engine. Here is a brief rundown to kick things off:

-SBC 350 + .060"
-650 Holley Double Pumper
-Stock cast 350 crank
-Speed Pro Hypereutectic Pistons; domed with valve reliefs, shaves off -11.8 cc http://www.summitracing.com/parts/sl...cp60/overview/
-487 casting 71' Corvette heads; pressed in studs, 76/77cc combustion chamber (can't remember which), 65cc exhaust ports, intake runner volume is between 160-170 cc, double springs good to .500 lift, 2.02/1.60 valves, exhaust ports ported
-Comp XE274 Cam, .490/.490 lift @ .050, 230/236 duration
-Hooker long tube headers
-RPM Air Gap intake
-MSD ignition (E-curve, Blaster 3, MSD Digital 6A)
-T56 6-speed
-10-bolt rear, 4.10s, moser axles/zexel torsen carrier/solid crush sleeve

I'm looking to snag a few more ponies out of this setup without changing anything in the short block. I feel like the RPM Air Gap works well on this current setup, and I've netted an 8.29 @ 85.2mph trap in the 1/8th mile, so it moves pretty good, but I think with the right heads I could see a little better power.

This, however, is an area I'm not well versed in. I'm looking for suggestions on a set of complete heads that would get a few more horses for me without running into clearance issues. I know that for the clearance you may need a few more specs, but this is all I can remember from when I assembled the engine.

Any help is appreciated.

Westech

well with your pistons you will need large chambers. if you want more power you can get a set of alu heads of ebay. or go all out and snag some trick flows. most you will get for 1500 bucks worth of heads is 20-30 hp. yeah thats a chunk just $$. I would get a set that cam handle 600 lift so if you ever dump in 1.6rockers you are safe. and in trick flow its only 100 bucks more not to be running at the max of the head. just my few cents.

plasmeh

iTrader: (10)

Thoughts on the AFR Eliminator Street heads? Any opinions on if this would be a good fit for my application and if I'd notice a power increase? (195cc intake runner/75cc combustion chamber/64 cc exhaust) http://www.summitracing.com/parts/af...make/chevrolet

Orr89RocZ

iTrader: (20)

Compared to stock 71 heads, you will make a ton more power with any aftermarket aluminum 190-200 cc head

plasmeh

iTrader: (10)

Orr89RocZ, the heads I posted I hear are highly regarded in the community. I think I can swing the price with the tax refund I'm getting this year - any set of 1.5 roller rockers you might suggest to go with them? I don't want to run the risk of clearance issues going to the 1.6 set, though a bit more lift would be nice.

305sbc

iTrader: (3)

Looks like a very good choice to me.
The runners are a little large, but AFRs have very good velocity and you have a lot of gear, so they should work fine.

edit: either Comp steel, or Harland Sharp aluminum roller rockers are both very good quality pieces IMO.

Orr89RocZ

iTrader: (20)

Afr are very good street heads. Definately work well and will make alot more power over what you have now. The heads usually come with hyd roller springs so may want to double check with afr to see what part number the flat tappet springs are. With a 1.6 rocker that combo should definately scoot.

Also check AD Performance for pricing. May get them abit cheaper there.

Another good choice and abit more budget friendly are jegs brand heads, aka pro-filers. 1000 bucks and a darn good head

plasmeh

iTrader: (10)

The Jeg's head's that are 195cc/72cc chambers are $580/each - pretty nice price! I'm a little worried that the 72cc chamber may bring my compression too high with my domed pistons for 93 octane, but I don't see any head offerings Jeg's brand with 75cc chambers - thoughts?

Also, you think I can use 1.6 roller rockers with the domed pistons without risking kissing anything? I'd love to be able to get either the Jeg's heads (as long as they will still rock my socks off like the AFRs) or the AFRs and use a 1.6 rocker.

Finally, I wasn't aware that there were different springs for different cam types - I thought if it advertised to .600 lift, for instance, that it means with either a roller cam or a flat tappet. I guess I'm showing my lack of knowledge here if I'm wrong.

Thanks for the help - keep it coming!

Orr89RocZ

iTrader: (20)

Need to look at pressures on the springs. Hyd rollers run greater pressure and that can wipe out flat tappet cams. Their core isnt as hard i dont think.

I will have to do some calcs. How does it run currently? I get near 11.2 to 1 comp as is and with iron heads thats race gas territory. Aluminum afr's will tolerate that, and the jegs might as well. Chambers are alittle different but should handle it. Jegs 72cc however will yeild closer to 11.8 to 1 which is bit to high with that cam.

Bit thicker gasket to make quench around .045-.050" should give 11.5-11.6 to 1 but still be iffy on 93 gas.

Cant comment on piston to valve. My feeling is you will have plenty of clearance but depends on that dome shape and where cam is installed. Degree it and check with clay

plasmeh

iTrader: (10)

I'm thinking of getting the 72cc Jegs heads, .045 gasket, and 1.5 rollers to keep things safe. I'm sure I'll still see a vast improvement. I've done some looking around online with others using similar spring pressures with the XE274 and no one seems to have issues. Comp even recommends close to what the Jeg's heads have for single springs. The issue seems to come back to people that are wiping lobes because they aren't using ZZDP oil or additives.

I think I'm down to selecting which spark plug to go with - anything you guys recommend that's cost friendly? I've been running R44T's for years now without an issue - any reason to change it up?

Orr89RocZ

iTrader: (20)

I run ngk plugs, part numbers will vary but most seem to be 3/4" reach, 14mm gasket seat, resistor type. Whatever is considered stock heat range, i would try 2 steps colder with higher compression. Thats around a 6-7 heat range in an ngk plug

DeltaElite121

Chad Speier's Econo Profilers. Either that, or the Dart Pro 1's. BRODIX also makes a decent head. AFR's are a good choice if you have the coin, but I still think there are better options. Chad has the best deal on the market for GOOD cylinder heads on a budget in my opinion.

plasmeh

iTrader: (10)

Something like this? http://www.summitracing.com/parts/ng...make/chevrolet

Orr89RocZ

iTrader: (20)

Yeah something like that. I'd wait til i bought heads first then get plugs and test fit them to see how they fit

plasmeh

iTrader: (10)

Good idea. That 14mmx3/4" is what the Jeg's heads call for, but we'll see. I appreciate everyone's help on this today. I'm putting together my build sheet and we'll go from there!

plasmeh

iTrader: (10)

Looking at the Pro-Filers website, looks like I can get the 195cc/72cc head with straight plugs, 2.05/1.6 valves, etc for roughly the same price as the Jeg's heads with 2.02/1.6 valves. Added value in moving to the 2.05 valve in my instance do you think?

http://www.profilerperformance.com/r.../sbc-23-degree

Orr89RocZ

iTrader: (20)

Dont need the 2.050 valve for that setup to be honest. You can run it but it wont make a difference imo.

plasmeh

iTrader: (10)

Thanks. Finally, it looks like Jeg's is having a sale on the 195cc/72cc/2.02/1.60 combo with angled plugs - $499 opposed to $549. I'm running the cheapo hedman longtubes with straight plugs currently - any idea of fitment issues with angled plugs? I imagine I'd have even more clearance than I currently do with the angled plugs.

Also, I have put together a tentative list of items for this head swap as follows:

Valve Cover Studs - Mr. Gasket Valve Cover Stud Kits 6330 - $13.95 -
http://www.summitracing.com/parts/mrg-6330/overview/

Valve Cover Grommets - Summit Racing® Valve Cover Grommets SUM-G3410 - $1.50/ea= $3.00 -
http://www.summitracing.com/parts/sum-g3410

Spark Plug Wire Loom - Summit Racing® Spark Plug Wire Separators SUM-890041 - $11.95 -
http://www.summitracing.com/parts/sum-890041

Cylinder Head Gaskets - Cometic Head Gaskets C5245-051 (.051 crush) - $93.99/ea= $187.98 -
http://www.summitracing.com/parts/cgt-c5245-051

Cylinder Heads - JEGS Performance Products 514024 - $499.99/ea= $999.98
http://www.jegs.com/i/JEGS-Performan...ductId=1593012

Pushrod length checker - Trick Flow® Adjustable Pushrod Length Checkers TFS-9001 - $11.95
http://www.summitracing.com/parts/tfs-9001/overview/
(Determining proper pushrod length - http://forums.chevyhiperformance.com...oller-rockers/)

ESTIMATED: Pushrods - Proform Pushrods 66891C - $66.95 -
http://www.summitracing.com/parts/pro-66891c/overview/

Rocker Arms (1.5 ratio) - COMP Cams High Energy Die Cast Aluminum Rocker Arms 17001-16 - $165.95 -
http://www.summitracing.com/parts/cca-17001-16

Intake Gasket Set - Fel-Pro Performance Intake Manifold Gasket Sets Q1206 - $16.95 -
http://www.summitracing.com/parts/fe...make/chevrolet

Header Gasket Set - JEGS Performance Products 210052 - $15.99 -
http://www.jegs.com/i/JEGS/555/210052/10002/-1

Valve Cover Gaskets - Summit Racing® Valve Cover Gaskets SUM-G2301 - $11.95
http://www.summitracing.com/parts/su...make/chevrolet

Spark Plugs - NGK G-Power Platinum Spark Plugs 7092 - $27.12 -
http://www.summitracing.com/parts/ng...make/chevrolet

TOTAL: $1,647.00

Orr89RocZ

iTrader: (20)

Cant comment on that. My hooker longtubes with afr heads that had L98 angle plug fit great. If they are close get spark plug boot protector sleeves

Johnny Blaze

iTrader: (15)

I'm pretty sure Jegs heads Are Profliers, with the Jegs name on them.

Orr89RocZ

iTrader: (20)

Yes they are, but they seem to be available in different valve diameters, giving head porters room to shape port to specific applications

plasmeh

iTrader: (10)

I'm actually having trouble finding a 4.060" head gasket. Almost all of the gaskets that I see that are available to ship before April from Summit say "O-ring of head or block is required" - what does this mean? Can someone help me find a decent .045" + head gasket?

plasmeh

iTrader: (10)

I found these:

http://www.summitracing.com/parts/cgt-c5245-051

They are quite pricey at $93.99/each, but I don't see any requirements for o-rings with these and they are .051" thickness which should put my compression in the ballpark of 11.4:1. Can someone please explain the o-ring thing to me? I remember when I bought head gaskets last time they only ran me about $50 for the set.

plasmeh

iTrader: (10)

Looks like I'm going with the Cometic gaskets I listed above. Everyone seems to swear by them. They are overkill for my application, but better to be safe than sorry I suppose.

With regard to the RHS heads - I think by the time I had work done on them to get them where I would need them, I'd be spending just about the same amount on them as the Jeg's heads.

Orr89RocZ

iTrader: (20)

Rhs is a decent out the box head but really benefit from port work. They are a good casting to work with. Could buy those and make more power over what you have now. Rhs heads that i have seem to want more timing than afr heads, almost like an L98 vette head.

If you cant find a 4.06" gasket try a 4.100". O-rings are grooves cut into block deck or head deck and actual o-rings are inserted to better seal the head to deck. For high pressure apps like alot of boost or nitrous

plasmeh

iTrader: (10)

It's ok to go large on the gasket?

Orr89RocZ

iTrader: (20)

You dont want to overhang into the chamber basically. Its ok to go alittle wider. I ran 4.1" gasket on my 4.030 bore. I run 4.16 on my 4.125" bore motor

plasmeh

iTrader: (10)

Orr, thanks for your input throughout this thread - you've been a big help. I'd be wise to listen to the words of a man who has a twin turbo'd ride.

plasmeh

iTrader: (10)

Just pulled the trigger on the cylinder heads and supporting hardware - can't wait! I found this rather interesting article that pits some similarly priced heads against eachother, including stock iron heads.

http://www.carcraft.com/techarticles...t/viewall.html