408 Stroker Build Suggestions

Mopar to ya said
It sits right at 500 hp and I run 93 octane pump gas. It is such a torque monster! I love this engine. It's not a great racer on the highway because at 80 mph the torque is not all there at that speed, but I never lose off the line. I've had it to 145 mph and had a lot to go. It's a great motor and you will never regret building it.

That build sounds really nice. Pretty similar to what I want to end up with in a lot of ways, so thanks for all the info, I'll definitely be using it. Seems killer.

Wyrmrider said
zsn
duplicate as much as possible the info given by Mopar to ya
get your head and compression nailed down before you buy a camshaft and etc
calculate your quench and try and get .030-.040 have that figured out and tentative gasket to get that dimension
what year block LA or Magnum and is it square already- check before spending $$$ because you do not know how much of a cut to square it up
did you specify LA shaft or Magnum Heads (and intake) just to be sure
have a straw man rocker picked out
unless you want to do B3 spacers forget roller tip and plan on adjustable Iron rockers preferably from Rocker Arm Specialists
read all 4 parts
B3 Racing Engines LLC - Mopar Rocker Arm Geometry Tech
get your head flows, straw man headers, compression figured out then fill out this form
Street Performance | Jones Cams
Best HR profiles IMHO

That calculator is awesome. I'm going to be filling that out tonight and seeing what it gives me. Thanks for the advice!

autoxcuda said
I run a smaller comp 274-S solid flat tappet cam and 9.7:1 compression, edelbrock “63cc” heads, scat kit: cast crank/I-beam/17cc Icon/balanced, M-1 single plane, 750+ cfm BG Silver Claw dbl,

Since you are looking for something real street freely I would limit yourself to 91 octane pump gas with 9.5-9.7:1 compression, flat tappet cam.

The heads and piston give me quench to help fight off detonation. If you need reduce compression, run the stock Fel Pro gasket that thicker. I run the thinner performance line gasket.

I think .500 NET lift is max for stock rockers. But stock rockers are 1.46:1 ratio. So you can get away with .515 or so advertised lift with flat tappet hydraulic cam

Add a edelbrock rpm intake, 750 dbl pump, TTI or Dougs headers... and you have 425-450 hp motor built economically that will fry street tires at will. Probably more.

I run ported heads, solid cam, comp roller rockers, bigger cam and single plane looking for a little higher power curves for when I occasionally go to the track and not dip below 3K rpm.

Pretty spot on to what I was wanting. It's nice to see all of these builds others have done and how awesome they turn out. 425-450 HP is pretty ideal, right around where I'd like to be. The rocker ratio information is super useful as well. Thanks!

Caco2120 said
For the type of engine you are describing, i would highly consider contacting @Johnny Mac. He is a manager at blueprint engines. And he also owns a 10 second 408 dart. Wether you want a short block, or long block 408, you cant even buy the parts for what blueprintengines.com can sell you an assembled offering with a warranty, and dyno tested. Just my 2 cents. Lots of happy blueprint customers on the board.

I have considered blueprint engines, but I think I'm going to build it on my own for this. Want to learn more about building V8s and the build itself is pretty enjoyable for me. Thanks for the suggestion, though.

AJ/FormS said
It sounds to me like; for your stated useage,
"I'm aiming for a streetable car with a very good low-end that will be fun and fast but still driveable near daily."
That the 408 might be overkill....Hang on, I'm not trying to rain on your parade.
It's just that if your budget is that tight, I would swap the stroker in a heartbeat, for the aluminum heads. The 367 practically falls together at 10.8 Scr with 63CC Eddies. And together with .....say that SEH 2832, it would make cylinder pressure around 175psi, and you can run E87 on that; I do. You can't run that much pressure at all with iron heads. And if you put 63cc iron heads on the stroker,and use that same 2832 cam your pressure might go too high for pumpgas. But let's say you somehow get it down to 160psi. At that point and below 3000rpm, your 408 might show similar performance to a 367, also below 3000 rpm.................... so......... say 80% of the time or more, the 367 would be sufficient. The 367, at 175psi, will spin 275/60-15 BFG-TAs to 50/60 mph with 3.91/4.10s easy. It will spin 325/50-15 Comp T/As to the same. Actually, mine does it with a 4 speed and 3.55s, so second gear is 6.82 ratio for me, whereas for you; 6.82 would require 4.70s, before factoring in the TC; so say minimum 4.10s, to absolutely annihilate the tires..
But
Where the 408 will come in handy is in third gear......... sometime after 85 mph. You go there much? Another reason to run the 408, is so you can run a hiway gear,and still have a strong bottom-end left over, without running a monster TC. And another is cylinder pressure; you can soften it up to run pump gas and again; still have a tire fryer.
The only reason I mention these things is because you said;
"Any input at all is appreciated. I have read a LOT about engine building but have not had much experience myself (yet),Thanks for your time and help"; And because your budget is so tight.
Up here, Canada, the Eddies and proper valvegear cost me about $3000, back in 1999, while stroker kits were about $2000/2500. I have never been sorry about my decision.
Whatever you decide, forget that 1850, and
Happy HotRodding

You definitely had me considering the 367, but for my usage, I still think the 408 will be the way to go. I'm aiming for a lot of lowend, but I also want to be able to run highway-capable gearing so I can use the car a lot for normal driving. I also want to be able to use pumpgas. I think these lend themselves well to the stroker. On top of that, I'm going to need new pistons anyway if I'm boring out the cylinders .030, so I figure why not just go with the stroker kit? It's a huge increase in cubes and it really isn't that much more when I'm going to have to get the pistons and work done on the crank anyway. I also figure I can always upgrade the heads later to take better advantage of the bottom end if I need to. Leaning towards porting them later on or doing a light port now and going from there later possibly. Thank you for the advice, though. The 367 is definitely still a good choice for what I want, and if I wasn't aiming for exactly the use scenarios I am, I might have gone with that instead. I do value the input a lot, even if it's telling me not to do what I had planned, it's still really useful to see the other options that I hadn't even considered. On the topic of cams, I haven't really looked into the Thumprs all that much. Focused more on the other offerings from Comp, so I'll take a look at those for sure. Sounds like it could be a good fit, thanks!

Wyrmrider said
A ray of sunshine
Horsepower in in the heads no matter which cu in you come up with the top end HP will be what the heads can provide
the torque below max hp will be more with more cu in
you can add the high buck heads later or get your heads ported later- you want your heads to be pulling their max from low to max rpm
so build the bottom end with a reasonable compression ratio
I much prefer closed chamber so take a look at what's available- that rules out the X and J and 915 even the 308 but you can get some EQ heads for not much more than prep work on the old iron heads- or check out the budget aluminum ones- just stay away from the open chamber ones as as far as I spec you would need KB quench head pistons
of course you could go that rout with stock heads and mill of the quench dome when you changed heads- done that several times just to optimize quench
a consideration is that the later heads have a better combustion chamber- and the 308 is OK
sorry I misread your HFT spec- somewhere I saw HR
set up right I've run 550 lift with stock rockers but no reason to go over .500 with stock type heads-and that's with a good pro valve job otherwise the flatten out at .450 and at .550 you will need custom pushrods with stock rockers
no free lunch
did you post your gears and all the rest?

This is what I am thinking about doing for the heads. Throwing the edelbrock heads on out of the box for now and porting them later once I've saved up more is looking like a solid option. What is the feasibility of using the SEH2832AL-10 with the edelbrock head springs and stock rockers until I can afford adjustable rockers to drop in later (thinking 1.6 might be better at that point, too, since looking at the flow numbers, I think the heads could use that extra lift enough to be worth the cost over the 1.5's)? My pushrods are toast, so I'll be buying new ones anyway (in addition to new lifters), but with adjustable rockers I should be able to use the same pushrods that I would use with stock rockers, correct? Getting all the gearing, weight, etc. information tonight. Got stuck at work a little late last night then had to catch up on some other stuff and there was a thunderstorm so I couldn't get outside to manually check the rear gears as I had hoped (I've got to jack the car up anyway to replace a parking brake cable, so I figure I might as well just count the driveshaft rotations to figure out the gearing while I'm down there). Thanks for the advice!