So recently I had a valve hit a piston in my #6 cylinder and it did a lot of damaged to my 355 build. Never really finish getting it dialed in. so I’m going to start building a 396 on E85 approx 13.1 compression 450-480rwhp NA and salvage what parts I can from my previous build. I’m going to try and finished this build by the end of fall and will be updating as I go, but as we all know how these things never go according to plan. My goal is high 10s NA and high 9s on spray with a t-56 and be street driven but I do plan on swapping to auto down the road either 4l80E w/trans brake or a TH-350 but that’s later on for sure. Still deciding on a few thing and will be updating and posting pic as I go but I have a good idea what my build is going to be. I checked off parts I already have.
Engine:
*Lt1 block with eagle 4 bolt mains
3.85 4340 Eagle or Ohio Crank
*6.00 Callies Compstar rods
*4.030 Mahle Powerpak /Rings +5cc
AFR 210cc race heads
A.i. Hyd. Custom Grind cam 24X int./25X exh. range
A.i. Ported Intake Monoblade
AS&M monoblade
Linked roller lifters
CC pushrods
*CC 1.6 rockers
*Melling oil pump
*Arp Hardware
*SLP lid conversion
*Comp Clutches stage 2.5

Exhaust:
OBX stepped headers 1 ¾-1 7/8
*Magnaflow cat-back and custom Y
*Cut out

Fuel system:
Aeromotive stealth 340 pumps (?)
*Speed Inc. Fuel line relocation
60# injectors

Nitrous:
N/O monoblade plate w/ 15lb bottle

Suspension:
*QA1 Front coil overs 300# springs
*PA Racing K-member w poly mounts
*Comp eng 3way rear shocks
*Lg G2 lower control arms
*UMI relocation brackets
*Tubular subframe connectors
*Adj. Panhard bar

Rear end:
*Stock with 3.73 for now
Upgrade w/ 9’’ next

Please chime in on if you think this build with meet my goal. And I’m still up in the air about my fuel set up. I’m trying to find a In-tank pump that can handle E85 any suggestions?thanks

 

LT1 block with eagle splayed caps

 

if you're well dialed, you should do better than high 10's. I don't see that rearend lasting very long, though. I'd get that situation taken care of before building power.

 

i was just making a realistic goal which is high 10s with a t56 now with a auto setup it should be mid 10s NA. and as for the rear end that will get swapped with a 9'' when Im done with the engine build.

 

12 bolt should be good enough. There are a few LT cars with 500hp to the wheels that held up with a 10 bolt for a short while. Not to mention you lose more power to the wheel with a 9” or an S60.

 

When it comes down to buying a rear end Im going to go with whatever rear end i could find for a good deal wether its a 9'', 12bolt, s60.

 

Sounds like a nice set up, I had Phil spec the cam for my 398, very nice person to work with. On the rear I would buy it new and get exactly what you want, I wish I would have done that. Problem with used rear ends they're never quite what you want, so by the time you factor in a gear swap, the cost between new and used starts to diminish.

 

BizZzatch350, as a Winter project I will be building a 396 LT1 shortblock for my car, and, I have three (3) HR cams lying around here which I think may be suitable for this (PCM limited) 7,000 RPM maximum 396 engine build of mine.

If you don't mind sharing your cam specs, what did Phil wind up spec'ing for your 398 build, and, if you have had your engine on the dyno ........ what RPM did your cam/engine peak at???? I'm really looking for a cam grind which would be "all in" by say 6,600-6,800 (max.) RPM.

TIA for any additional info about your set up.

 

97REaper, you do know that the 4.030" Mahle Power Pak pistons from your 355 engine will NOT work with your 396 engine build, with its 3.875" stroke crank ...... right?

 

The cam is a hydraulic 24x/25x/110 .603 lift, the car will be coming apart here shortly for the new short block, so I can't comment on what it will peak. I only drive the car maybe 500 miles a year if that so having daily driver qualities wasn't an issue. Hopefully with this new set up I'll find the time to try and drive it more. I don't have a LT1 based PCM, my car is swapped to a 24X set up and I also no longer have an LT1 intake manifold, I am running a converted single plane. Heads wise they're Dart Pro-1s, done locally by Robert at Late Model Engines.

 

BizZzatch350, Thanks! for sharing that info, and, of course ....... Good Luck! with your new build.

 

Thanks bro...
Yeah you got a good point on that ill keep that in mind.

 

And why would that be? last time i check it will work

 

Your pistons will need to match up with the longer stroke; 3.48 to 3.875. Pin location makes a big difference.

 

They do match up. I bought the rotating assembly thru A.I. when they use to sell kits. I could of used a 5.85'' rod or 6.0'' rod. come on people. smh

 

he is right the compression height is different between the two pistons. A 1.10 compression height with the 396 and a 1.58 for the 355.

 

ok a 396 stroker consist of a .30 over piston 3.875 crank 6.00 Rod which is what I have. The pistons aren't that thick because of the longer rod and I know that but with the right deck hight on the block with the right gasket and milled heads I can net my compression goal. Trust me these pistons and rods will work other people have them in there 396.

 

I have a somewhat similar setup, 13.5:1 385, 24x/25x .61x/.62x 110 custom LE cam, 6" rods, M29 with a stock 3.42 rear, mild 185cc EB Porting heads, and it is very streetable to me, it's all in the tune. Also, I am running a Walbro pump and 60# injectors and a stock replacement FPR, and according to my wideband, at 6800 RPM I show 11.8 A/F ratio, so the fueling appears to be keeping up. With 11 more ci, better heads, and steeper gears, it should be easily over 450rwhp and very fun.

 

Short answer first, 97REaper ..... you are half right. Your 6.0 inch rods will work fine, but .......... your 355 pistons will NOT.

Long answer now:

On an uncut (i.e. undecked) LT1 block the deck height is 9.025". Just using this 9.025" deck height as an example, to get your pistons flush with your block deck, your rod length plus your piston compression height plus one-half of your crank stroke must equal that 9.025' deck height.

For a 3.480" crank (i.e. 350/355 SBC engine), and 6.0" rod, your piston compression height works out to be 1.285".

For a 3.875" crank (i.e. 389/396 SBC engine), and 6.0" rod, your piston compression height works out to be 1.0875".

Soooooooo ....... in this example, if you just took those 1.285" compression height pistons and put them in your 396 build ........ your pistons would "stick out" .1975" inches ABOVE your 9.025" block deck!!!

Believe me, and mguidry629, and nitrous2fast ...... you cannot re-use your 355 build pistons in your 396 build.

 

I've got a 244/256 .381 on a 105. The LSA is a little tight for E85 but the longish exhaust would work well with that stroke and full exhaust. Would really make a ridiculous amount of torque advanced a degree or two. I made 480/459 with a 240/252 107LSA HR on 100 unleaded with a 6speed, 9" and 28" bias ply MTs. 383 with worked on AFRs.