Need advice on 347 Build up.

[Thomas A]

Well, the time has come. After almost a year of strongly disliking my current motor, I've decided to part it out and build something else. I'm going to need a lot of help and advice though. 90% of what I know about engines and setups relates to the 3.8L. So, any advice would be much appreciated! I have found searching the Corral a waste of time. One post will say something is the greatest ever and another will say it's the biggest pile of crap ever, so that isn't going to help me out any.

I'm looking to build an EFI 347 Stroker that will still be fairly streetable. My goal is 400rwhp and 400rwtq. I'm looking at running NA on pump gas at 10.4:1 compression. I guess my theory behind this is to run the best possible heads/cam/intake combo to achieve this goal NA. Do you think that this goal is even reasonable?

BLOCK:
I'm strongly leaning towards the FRPP roller block, 2 bolt main, cast crank, SAE 4130 forged rods, Federal Mogul bearings, and hypereutectic pistons. My only concern is if it going to be strong enough. I don't plan on every spraying it or adding a blower. I really want to keep it NA. The next option would be a DSS block, but that's about $500 more. I don't plan on spinning it much past 6,000rpm. Also, windage tray or stud girdle? Advice on the block??

HEADS:
I think I've got my mind made up here. Looking at the Jegs/Kaase aluminum heads. 7/16" stud mounted rockers, 247cc intake runners, 1.375 exhuast ports, 60cc CNC chambers, 2.10"/1.60" stainless valves. The other possibility is the Trick Flow Twisted Wedge heads. They are about $500 less, but from what I've read and heard, not as good of a head. The heads is one place that I went cheap and screwed up on my current motor, so I don't want to make that mistake again. Advice??

Intakes:
I've been looking at the Trick Flow Tack Heat upper and lower intake with a 75mm TB. The rpm range is 1500-6500 which is right were I am looking to be. I've also kinda been looking at the FRPP GT-40 manifolds. They claim to be the best, but who knows? They are another $150, but I am wondering about how streetable they would be? Not really sure between the two??

Cam:
I have nooo clue on the cam. When I was originally looking at the TFS TW heads, I was just going to go with thier matching cam. Now that I will probably go with the Kaase heads, I'm not sure what kind of cam to run. I totally screwed up on the cam choice on my current motor, so I don't want to repeat that mistake. Again, I think something in the 1500-6500 range and will still idle half way decently. Most likely be looking at 1.6 or 1.7 roller rockers. I really have no idea of what cam I'd like to use, so any advice on lift and duration would be much appreciated!

Fuel:
I'm not really sure of the fuel needs on a NA application. I'm running 42# injectors in my SC right now, but I know that SC vs. NA is totally different. Would 42# be too much for this engine? Would 30# work better? Also, adjustable fuel pressure regulator of stock? I'm currently running a Walbro 255FI pump. Do you think that will be able to keep up with a motor like this?

Other:
I'm planning on running all MSD ignition, high flow oil and water pumps, Griffen radiator, and some coated long tube headers with 2.5" high flow cats going back to a dual in, single out 3" resonator, 3" pipe back, and then Y it into a dual 2.5" Dynomax mandrel bent setup. Probably just some FRPP lifters, timing chaing set, intake pipe, etc. Pro-M MAF for sure, most likely thier 75mm unit. March underdrives and such. Anything else I should for sure consider?

Thomas :read:

 

[OLD FART]

I would call a reputable shop and get a package deal with known HP and TQ numbers so that all the parts will work well together.
CHP and DSS are very good. If you piece it together, you have nobody to "yell at" when it don't work right. There are several companies out there that offer what you're looking for, but be prepared to drop some serious $$$ to complete the swap. Don't just do it half-azz, do it right or not at all. Every shortcut you take during the buildup will be one more problem you'll face later on. You're doing right by asking for advice, but anyone who can tell you specifically what parts to buy and assemble should probably be paid for the amount of time and energy it takes to compile such a list that is thoroughly researched enough to be bulletproof and deliver what you are wanting reliably. Leave it to the pros and just buy everything from one source (unless it's obvious they're taking your head off on prices). Just my HO.
Good luck.

 

[diesel_daddy]

First off I am no expert but I do have a few suggestions for your combination. Others can feel free to correct me if I am wrong.

1) The heads you are looking at are way too big to be streetable. They will probably not make power until around the 4000 rpm mark. I would suggest a set of AFR 185s or 205s to reach your goal HP.

2) 30# injectors should be plenty. I have read that they are good to about 450 HP. Also it seems that when you get too large with the injectors tuning becomes more difficult.

3) you can use the intake you mentioned. something like it or a performer rpm would probably work fine.

4) Don't over cam. This can be done very easily. Call comp or lunati or the cam manufacturer of your choice. Tell them your set up and the powerband you want to operate in. Let them grind you a custom cam for your application instead of buying one off of the shelf. This is usually a little more expensive but results in a better match.

I think with the parts you mentioned you are going to have to turn 7000 rpms or more to see any real power. As I said before I am not an expert and these are just my opinions, but I think you can reach your horsepower goal without huge intake ports and monster cams and keep it much more streetable.

Good luck!!!!