scj's or p-51's

OK guys I need some honest advice/opinions on this. I am looking into purchasing either the scj heads Lem has on sale for $577 each or a set of p-51's on Kaase's site bare they are $799 each. Now I am working on a limited budget so I was wondering which will be a better deal use out of the box p-51 ($2450 from Kaase's site) or buy the scj's and have them ported by someone on here(price unknown)? I have looked at flow numbers and it appears that out of the box p-51's are better than scj's fully ported but how will each actually perform? These will be on a 4.3 stroke, 4.5 bore block with a victor dominator intake matched to the heads a 1250 dommy and a custom cam for these heads? Sorry bout the long post just tryng to convince myself on my best way to proceed.

Charlie has a 533" SCJ deal that made 880 hp...matter of fact it may be for sale .

Lem what would an approx. cost for fully ported scj set up for a solid roller around .800 lift?

I'm not Lem, but I can answer the question, because Lawes and I do the porting. Anyway, it $950 for a set fully ported and flow tested. Quite often we redo the exhaust valve job in order to gain additional flow, and that would be $100 extra for the exhaust valve job. If you are on a tight budget, we can do pocket porting for $475, however they won't be flow tested.

Hope this helps,

Those SCJ's with Charlie, and Lawes "magic rub" are STILL a better deal than the P51's from Kaase! $2,204.00 for a set of killer heads - oh, if i hadn't already sunk all my money into my A429's - oh well, maybe next time around.

Wayne (SAWDOFF) Pearce

OK if I am understanding correctly that means the heads are $577 each ($1154) + $950 for port work + $100 for reworked valve job for a total of $2204 and I still have to get valves, springs, retainers, and locks. Is this correct.

Mr. Pearce so you believe the scj's done by charlie will out perform the out of box p-51's even though according to flow numbers previously posted in other threads the p-51's outflow the scj's.

Again I am just wanting honest opinions here before I make a decision. I am also thinking of the future and with scj's they will be maxxed out (i think) and p-51's will allow for growth in the future.

lghting94 wrote: p-51's will allow for growth in the future.

yes indeed...

if you are running a 4.5 bore then you likely have an aftermarket block (right?), so you it's likely you will build again sometime in the future.

If he has any, get them from Mr. Evans.

lghting94 wrote:Mr. Pearce so you believe the scj's done by charlie will out perform the out of box p-51's even though according to flow numbers previously posted in other threads the p-51's outflow the scj's.

Again I am just wanting honest opinions here before I make a decision. I am also thinking of the future and with scj's they will be maxxed out (i think) and p-51's will allow for growth in the future.

Flow numbers, FLOW NUMBERS, flow numbers ... you huys are SO obsessed with flow numbers it makes me wanta puke.

Flow numbers are only PART of the equation

You didn't ask about any future growth ... you originally asked about RIGHT NOW !!!

Fact call Lem and trust what he says .He will steer you right.

[quote="lghting94"]Lem what would an approx. cost for fully ported scj set up for a solid roller around .800 lift?[/quote
There are several ways to skin that cat.......springs , retainers , etc . All of it effects the price . I'd be happy to give you a shout to better understand your needs/budget .

by rmcomprandy on December 4th 2009, 9:07 am

Flow numbers, FLOW NUMBERS, flow numbers ... you huys are SO obsessed with flow numbers it makes me wanta puke.

Flow numbers are only PART of the equation

You didn't ask about any future growth ... you originally asked about RIGHT NOW !!!

Randy Yes I understand I probably didnt ask the completely correct question the first time but I was trying to understand more than just the flow numbers and this is why I am trying to ask the questions before I buy something.

by windsor on December 4th 2009, 8:52 am
if you are running a 4.5 bore then you likely have an aftermarket block (right?), so you it's likely you will build again sometime in the future

Actually I have a factory block that will go the 4.500 bore so that is what I plan on using

Lem I will try and call you later today(at the number above)to discuss this with you I appreciate everyone's help.

lghting94 wrote:

Actually I have a factory block that will go the 4.500 bore so that is what I plan on using

I want to comment here. What you are contemplating building is not going to be a toy no matter which head you use. All I am is saying is take a hard look at what you will be investing in the rest of your engine before using a production block.

An a 460 or eliminator block is a bargain when you look at the cost of 4 bolt caps/etc of modifying a stock block and chancing it will live.

by KY JELLY on December 4th 2009, 12:15 pm
I want to comment here. What you are contemplating building is not going to be a toy no matter which head you use. All I am is saying is take a hard look at what you will be investing in the rest of your engine before using a production block.

An a 460 or eliminator block is a bargain when you look at the cost of 4 bolt caps/etc of modifying a stock block and chancing it will live.

Randy I am checking all my options right now and getting all my ducks in a row, I do have a stock block that will go the 4.500 bore and currently that is the plan but if things work out where I can go with the a-460 block that is what I would like to do.

Also I did call and talk to Lem about the heads and he was very helpful in answering my questions for what I am planning once everything is finalized I will let everyone know how it turns out.

the p51 head had a better chamber, thats what i would start with,then worry about flow,or port work

I was trying to say that a set of SCJ heads with the added cost of the port work was STILL cheaper than the P51's "out of the box" from Kaase. I believe that the ported SCJ's would more than hold their own against the box stock P51's. If all things were equal, I imagine the P51's would have the edge. But as was said before "flow numbers don't tell the whole story".

Wayne (SAWDOFF) Pearce

KY JELLY wrote:

lghting94 wrote:

Actually I have a factory block that will go the 4.500 bore so that is what I plan on using

I want to comment here. What you are contemplating building is not going to be a toy no matter which head you use. All I am is saying is take a hard look at what you will be investing in the rest of your engine before using a production block.

An a 460 or eliminator block is a bargain when you look at the cost of 4 bolt caps/etc of modifying a stock block and chancing it will live.

X2. OK, so it will go to 4.500", but that's all it will go, and I guarantee you will want to go bigger down the road. Do it right the first time and save yourself some grief. No one is trying to rain on your parade, just trying to save you some money in the long run...

BOSS 429 wrote:the p51 head had a better chamber, thats what i would start with,then worry about flow,or port work

From Jon Kaase site:
"So what's the difference between this new P-51 head and the Ford Motorsport SCJ? First we made some changes in the chamber and then had them CNC machined so they would all be the same. Then we made some changes in the water jacket to allow for more aggressive porting at the intake short turn and left side wall. When porting the SCJ's, many times we would run into water above the intake seat, close to the top of the short turn. We then set up a program to CNC under both seats, down in the bowls and to the top of the short turns. The goal is to flow about 400 cfm on the intake, 250 on the exhaust. The real magic in this head though, is the intake flow at .400" and .500" lift. One of the big complaints of the SCJ head is that some of the rocker arms don't meet the valve tip correctly. Also, if you use longer valves for more spring height, the problem gets worse. We have changed the rocker stud angles and positions to accommodate most rocker arms and valve lengths. Yes, new stud girdles are being made at Jomar. We are also having .100" long, custom valves produced. The valve guide angles and locations are the same as the Ford Motorsport SCJ's. The pistons usually don't need an exhaust valve relief, while the intake relief will almost never need to be deeper than .150". The intake face, exhaust face and the valve cover surface are also the same as the SCJ's. "

So there were a few other issued with the SCJ head that Jon corrected with the P-51

lghting94 wrote:I am looking into purchasing either the scj heads Lem has on sale for $577 each or a set of p-51's on Kaase's site bare they are $799 each.

So ....... Have you made a decision?

I am still weighing my options and discussing this with my engine builder also, as well aswaiting to see how my funds work out this winter. Afer talking to Lem the other day I have alot to think about as to where exactly I want this combo to go. I am not the kind of person to just spend money I like to look at every angle I can think of and plan everything I possibly can before I start then I will start collecting the parts for the build as my funds allow. I have a block that will work but as KyMustang and Nevs pointed out I am maxxing it out if I use it so I will be looking at the a-460 and eliminator blocks aswell, would like to find a used one but that looks to be near impossible. When this engine is built I will let everyone know what I go with and what horsepower and torque it mqkes because it will be dynoed when completed not for the numbers but for a proper tune-up to start with. Thank You for your interest.

The Pope wrote:

lghting94 wrote:I am looking into purchasing either the scj heads Lem has on sale for $577 each or a set of p-51's on Kaase's site bare they are $799 each.

So ....... Have you made a decision?

You have the negative image of my truck. Freaky !!!




I bought the SCJ's. They will probably be fast enough to scare the $h!t out of me.

cletus I have a supercab f-150 4x4 with that same paint scheme but not that good a paint job yet probably won't be red and white when i'm done

lghting94 wrote:cletus I have a supercab f-150 4x4 with that same paint scheme but not that good a paint job yet probably won't be red and white when i'm done

The internet makes all our paint jobs look better than they are.


Like that country song. "I'm so much cooler on line."

lghting94 wrote:I am still weighing my options and discussing this with my engine builder also, as well aswaiting to see how my funds work out this winter. Afer talking to Lem the other day I have alot to think about as to where exactly I want this combo to go. I am not the kind of person to just spend money I like to look at every angle I can think of and plan everything I possibly can before I start then I will start collecting the parts for the build as my funds allow. I have a block that will work but as KyMustang and Nevs pointed out I am maxxing it out if I use it so I will be looking at the a-460 and eliminator blocks aswell, would like to find a used one but that looks to be near impossible. When this engine is built I will let everyone know what I go with and what horsepower and torque it mqkes because it will be dynoed when completed not for the numbers but for a proper tune-up to start with. Thank You for your interest.

Lghting94,

We are traveling down that same road you are looking to turn onto--we are a few rest stops ahead of you.

The block and crank are the foundation for everything you do now and want to do down the road--spend your money there! Our budget was limited so we got an A-460 block and Bryant crank but used our old SCJ heads. I plan on upgrading to A-460/Thor heads and when we do our block and crank will still work.

I don't know what "out of the box" P-51s would do on our motor but the SCJ heads dynod at 880 hp. Lem had them rubbed on and put in some 2.25 intake valves vs the 2.19s.

When my biggy bank is full again we will go from 572 up to 604 or better, slap a set of Thor BTs on it, and go looking for Mr. Bruno

Bruce