My 408 or 414 build?

I'm building my engine at school in one of my classes (Tech School) so I've been looking at parts to make sure I buy the right stuff. I want to start with a 6.0 block, and obviously get it punched out. What's the bore used for the 408 and 414? I found the eagle kit for $2400 +/-, I already have ARP rod bolts, I'll do ARP head studs also. As for the heads I'm liking the patriot cnc'd LS6 heads with the 59cc chambers. The cam I'm still unsure of but thinking in the area of 230/234 .605/.615 112. I want to build a high compression N/A (pump gas though) street/strip setup. I'll probably do the TBSS manifold and the nick williams 92mm T-body. As far as injectors go I'm going to try some 42's, but possibly might go with 60's if you guys think I'll need them. Any advice I can get will be awesome, I've been reading a lot on here but it seems like a lot are built for boost, so I still have some unanswered questions! I have $2500 to spend on parts now, and I'll take out a student loan to finish it up. I'd like to keep the total around $4000 for parts because I'll be doing all the machine work and assembly. Thanks!

http://www.eaglerod.com/index.php?op...d=33&Itemid=40

(either the 12917 or 12926 kit)

if you run a 4.030 u will have a 408 with a stroker crank. if you bore to a 414 u wont have a room do rebore and if anything happens u have a really heavy and expensive paper weight. If your going NA IMO put a good cam and agood set of heads on a 6.0 block and you will have a ton of power. If you get bored with that put a little spray on it. there are lot guys on here with some really fast stock internaled 6.0s.
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i think he is talking about the 4.100in crank which i am NOT a fan of.... i like square motors and a 408 is damn close to square. Also get parts from a machine shop i know i payed less than 2500 on my rotating assy. Also make sure u have arp 2000 rod bolts i have also heard nothing good about patriot heads, What tech school are you going to? Therese alot more things i want to say about this build cause i effed mine up at my "tech school build" and i dont want you to do the same but im pretty drunk right now sooo... N/A all you will need is 42lbs injectors and go with 11.5-12.0 compression. There is so much to consider here and there is ways to cut cost without cutting our build at the moment like staying with stock heads and cam and springs, focus on the short block....

Luke, I'm going to MATC in Madison, WI. I'm taking a 2 year auto technician program here. I'm looking at the 4.000" crank because I'd like to do as close to a 4"x4" as possible. I also looked at the PRC heads but I'd have to get them milled because I want 59cc-62cc chambers to make 12:1. That'd be awesome if you could pm me the things you did wrong so I make sure that all goes well. Thanks.

I would worry less about milling your heads and more about getting the right pistons. Like i said before Focus on the Short block, pistons is what you need to worry about most, get a domed piston it will probably still be a -cc piston but it will be domed with valve reliefs, yes you will want to mill the heads some to get a nice flat surface but were talking .005''. eagle rods and crank and fine unless you want to go with a callies crank they make one thats cheaper than the eagle and a couple that are more expensive than the eagle. any of them are good in fact in my new motor im going to be running the cheap callies its a "c series" and its under 600$ For pistons i like wiseco. Obviously they will be a 4.030'' bore or if you want a true square motor a 4.000''. Then the important parts... BEARINGS AND RINGS i like acl bearings, they are a more accurate bearing. make sure you get the right clearances. At school they should have a good idea what you need but check on-line and with the big ls engine builders to see what kind of clearances they run, what the school has for "race clearances" might be to tight for a ls motor, or to lose. Then on the rings id run a wiseco GFX if you want to spray this beast. and then make sure you gap them right. This is partly where i messed up my gap was to big, and i was running to light weight of oil and i had horrible oil consumption, i could burn a qt in about 3-4 days and thats just cursing/ break in. If you find at this point you have spent to much money then good. Stay with stock ported 243' and your current cam it wont hurt anything it will just feel under powered (which it will be) and then get you heads ported by a pro, Jon, ricky, and kurt really like there guy "junior" there in austin. There is also greg good and wcch. All depends how much you want to spend. Then the cam, get a custom ground obviously i like pat-g or HKE, (mine is HKE speced) There should be some big shops in your neck of the woods that can a good job as well. TBSS intake will work but not the greatest you could probably get it ported and it would work well, but still not going to flow like a fast would but a under 5k budget really dosent allow for a fast intake (thats why i went with a ported ls3) and like i said 42's are fine for a N/A motor. The 917 kit seems to be closest but its a kit and kits bother me

Be careful on your compression. 12:1 is pushing it for pump gas. My last motor was 12.05:1 and I could only get gas at a select few stations that seemed to have a better blend. You will know it when you got bad gas. Detonation like crazy. I would stick with 11.8:1 max for pump gas IMO. If its a Iron block I like to set up mains at 0.0025 to 0.0028 and rods the same. This works well for the builds I've done and is also what a lot of the Big LS builders use for specs. Like Luke said, ACL race bearings are awesome. See if you can find a used 90mm FAST intake. They are pretty cheap and will shine on the bigger cubes with a little port work. Get a Callies crank if you like flatter journals compared to Eagles that tend to taper. Eagle H-beams with 8740 bolts are fine. Wiseco pistons with GFX rings gapped accordingly. I would do a 408 also over a 414

Before installing any rod bearings check them for flatness using a dial indicator. Slide the bearing under it to see how much bow worked into the bearing when it was rolled to form the arc to fit the connecting rod. I have seen over .001" taper across one insert. I would not accept more than .0002".

Awesome info guys thanks a ton! Is there really any benefit to the tapered journals opposed to the flatter ones? anything to do with oiling or bearings? I'll go with the 408 because it seems to be the closest to a square setup and be somewhat easy to find parts for. Anything else you can think of let me know.

tapered journal will cause excess wear on the bearing and also cause side loading of the connecting rod in the direction of the smaller end on the journal.

FWIW, King aluminum racing bearings are pretty good, too. They're the bearings the pros use on the 1000+ HP 2jz engines. :thumb: