Thread: Opinions on heads.

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Im still gathering parts for my BB build. Its a 454 .030 block with stock crank, stock rods with ARP hardware. Pistons are TRW L2349 F .030 pistons. Cam is a hydraulic flat tappet: Adv Dur 276/284; @.050 233/241; .554/.572; 110 LSA. Going into my 66 Chevelle SS. TH 400 with 28-3000 stall; 3.73:1 rear gears. Dual plane intake and carb not purchased yet. Car will be street, occasional strip, not a daily driver.

SO Ive been sold on using my 781 heads....opening to 2.19/1.88 SS vavles, bowl work for porting etc. Problem Im having is this. Most places local to me machine shop wise want about $1K for the parts and work; which Im not doubting is worht thier expetise.....I have other sources out of state for as low as $750-800 but by the time shipping is all said and done, Im still at $1K. I dont mind spending thatg if its the smartest way to go, but is it? I question would it be more beneficial to purchase say a set of Merlin O ports which I think can be had new for $1400. I can sell my 781's for $150-200 as is and I have new heads for about $200 more than what my 781's would have cost. Then there is Summit's new iron head for like $1250., but its a rect port with 305cc runners which I beleive is a little too big. Again I'm looking for some opinions and guadance from the pro's here such as Pat Erik etc. Thaks for reading and those who respond!

Check summit and jegs they have very good prices and products for about the same price. Also check racingjunk.com they sell a lot of used parts , buyer beware. I think Pat on here has plenty of used parts and could help you out a little more. It might be a better idea to just get you some performance heads instead of reworking the stock ones . The stock ones will not flow all that great and it will take a lot of cash to get them even close to flowing good numbers. That money could be spent on quality heads

I'd go for the merlin heads, they are going to flow more than your 781's even with the bowl blend and bigger valves. And they also come with new springs, retainers, etc., which you are going to have to buy also. I believe the Merlin heads flow about 280cfm out of the box, so with a bowl blend and minor pocket port work you will be over 300cfm. And for a couple hundred $ more I think it's well worth it.

Originally Posted by 30-A Rider

Im still gathering parts for my BB build. Its a 454 .030 block with stock crank, stock rods with ARP hardware. Pistons are TRW L2349 F .030 pistons. Cam is a hydraulic flat tappet: Adv Dur 276/284; @.050 233/241; .554/.572; 110 LSA. Going into my 66 Chevelle SS. TH 400 with 28-3000 stall; 3.73:1 rear gears. Dual plane intake and carb not purchased yet. Car will be street, occasional strip, not a daily driver.

SO Ive been sold on using my 781 heads....opening to 2.19/1.88 SS vavles, bowl work for porting etc. Problem Im having is this. Most places local to me machine shop wise want about $1K for the parts and work; which Im not doubting is worht thier expetise.....I have other sources out of state for as low as $750-800 but by the time shipping is all said and done, Im still at $1K. I dont mind spending thatg if its the smartest way to go, but is it? I question would it be more beneficial to purchase say a set of Merlin O ports which I think can be had new for $1400. I can sell my 781's for $150-200 as is and I have new heads for about $200 more than what my 781's would have cost. Then there is Summit's new iron head for like $1250., but its a rect port with 305cc runners which I beleive is a little too big. Again I'm looking for some opinions and guadance from the pro's here such as Pat Erik etc. Thaks for reading and those who respond!

I would run the Merlin oval ports.
Like you said the 305 cc runner heads are to large.

Thanks to those who have respionded so far.... but 70x viewed. 3 responses? Anyone else? Pat? Tech inspector? ?

If you're gonna stick with that combo (cam, etc) Go with the merlin attitude (or equivilent) If you wish to keep the 781's, Drop the cam back, say no more than 515 lift on intake. Do the bowl work with corresponding valves like you mentioned. It doesn't require "huge" parts and peices to aquire what you want. Just good combinations. If your ambition to go "big" is where you want to go, Then by all means, go with the Merlins or equal product.

Originally Posted by nitrowarrior

If you're gonna stick with that combo (cam, etc) Go with the merlin attitude (or equivilent) If you wish to keep the 781's, Drop the cam back, say no more than 515 lift on intake. Do the bowl work with corresponding valves like you mentioned. It doesn't require "huge" parts and peices to aquire what you want. Just good combinations. If your ambition to go "big" is where you want to go, Then by all means, go with the Merlins or equal product.

Im confused, not doubting you. Was always told and under the impression to get good streetable power out of 781 heads was not so much the duration but high lift. Never with all the recomendations I have gotten has anyone recomended such low lift as you did....515 is very very mild for a big block no?

Not at all. If you want to go a tad bigger, put a slightly larger "Stick" in it like 545 to 555 lift on intake. The 781 is a respectable street head if you can find a set of 990's go with that and your cam combo you chose is gonna do it better. I'm trying give a better perspective on the heads you have. By all means, they're not bad at all. It's just you can stay within budget with a good pair of iron heads like the 990's and get a touch more for your buck. I never want to spend your money like it was mine. Over camming can kill what you're trying to do as much as under camming. Just trying to fill in the spaces of good combos. By the way what cam manufacturer were you referring to when you originally posted? Depending on their grind it could still work well.

Originally Posted by nitrowarrior

Not at all. If you want to go a tad bigger, put a slightly larger "Stick" in it like 545 to 555 lift on intake. The 781 is a respectable street head if you can find a set of 990's go with that and your cam combo you chose is gonna do it better. I'm trying give a better perspective on the heads you have. By all means, they're not bad at all. It's just you can stay within budget with a good pair of iron heads like the 990's and get a touch more for your buck. I never want to spend your money like it was mine. Over camming can kill what you're trying to do as much as under camming. Just trying to fill in the spaces of good combos. By the way what cam manufacturer were you referring to when you originally posted? Depending on their grind it could still work well.

With a port volume of around 320 cc's I would not even look at a set of 990's un-less you have your 454 going to 7,000 rpm's.
A set of 781's with 2.19/1.88 valves is all you need in a 5,500 to 6,000 rpm engine.

I stumbled across this yesterday ...................

990 heads with 25 passes on them for $75?

sfbay.craigslist.org/pen/pts/311895525.html

Kitz

Originally Posted by nitrowarrior

Not at all. If you want to go a tad bigger, put a slightly larger "Stick" in it like 545 to 555 lift on intake. The 781 is a respectable street head if you can find a set of 990's go with that and your cam combo you chose is gonna do it better. I'm trying give a better perspective on the heads you have. By all means, they're not bad at all. It's just you can stay within budget with a good pair of iron heads like the 990's and get a touch more for your buck. I never want to spend your money like it was mine. Over camming can kill what you're trying to do as much as under camming. Just trying to fill in the spaces of good combos. By the way what cam manufacturer were you referring to when you originally posted? Depending on their grind it could still work well.

Cam I was planning on was recomended to me by UD Harlod who developed the Lunati VooDoo cam pt #60204. Spec to refresh are : Adv Dur 276/284; @ 050" lift 233/241; .554/.572 lift; 110 LSA. According to Lunati need 10:1 compression which is where I should be at with 119cc heads and trw domed pistons, and also stated needs 2800-3000 stall which I was planning on going with 3000 stall and 3.73 Gears.

Actually to add to this....... Ud Harold actually initially recomended a Lunati 402A3LUN which is a solid cam at : 276/284 @ .020; 243/251 @ .050; .586/.600 on 110 LSA.

He recomended this because he stated he loves this cam and it is what he considers to be "The Classic Big Block Cam"..I just decided to go with hydraulic flat tappet cause its all I have expereince with.

60204........That is a very torque, hard pulling cam. The absolute max for your heads if prepped right. It also allows for future head swaps without any changes other than valve gear when neccessary. Run with it, Learn the tuning for drivability and get in there and enjoy. By the way, why the heck do the machine shops charge so much there? That's insane.

Originally Posted by nitrowarrior

60204......... By the way, why the heck do the machine shops charge so much there? That's insane.

I dont know. Regardless though, every shop or private party Ive spoke to abou my heads wants $750 and up to do the work. so I send out of state for $750 plus probably 100-200 shipping there and back...or I stay local and pay $1000. either way its the same. I dont mind spending the $$$$$....my original question was to make sure I was spending iwsely on the 781's or if I should spend that money on a set of Merlins is all.


Thanks for everyone's response.

No biggie... I was blown away with the pricing, that's all.