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Opinions on my 396 build

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Old Sep 27, 2005 | 03:36 PM
  #1  
Chris90Formula's Avatar
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From: Pompton Plains, NJ
Opinions on my 396 build

I know that there have been hundreds of these posts, but here is another buildup. I'm looking for opinions on my 396 stroker I'm about to build. I haven't seen to may people building 396's as compared to 383's. But the rotating assemblies are the same price so I'm going to go for the extra 13 cubes. I only put about 5,000 miles a year on my car so I'm not worried about the extra side wall wear. This will be replacing my 305 tpi in my Formula. I will be purchasing the machined block and rotating assembly and putting it together myself. It will remain fuel injected with a modified LT-1 intake. The car will be used for street/strip. It won't be my daily driver, but I want it to be able to be driven on short and long trips regularly. With this in mind I want to get as much horsepower out of it as possible. I think I can achieve around 475 hp. I calculate a compression ratio of 10.9 with a .039 head gasket. The motor should spin safely to 6,000 rpm. I've done may searches, but I'm still not sure about the cam, rings, fuel pump, etc. So please see my list and provide comments.
Thanks,
Chris

Block
late mode 350 one-piece rms roller block bored .030 over, zero deck

Rotating assy
Eagle ESP Forged internal balance
4340 H-beam rods (I'm going with the H-beams because they won't have any interference issues with the cam)
4340 crank - 3.875 stroke
SRP Forged pistons 5cc relief's
JE plasma file fit rings (should I upgrade to Total Seal gapless?)
Clevite 77 HP bearings

Heads
AFR 195
68 cc combustion chamber (should I have the spring pockets opened up? Is there any need to go to 7/16 studs?)
Upgrade springs to CompCams 986-16
CompCams Pro magnum roller rockers (1.52 or 1.6 ratio? )
Pushrods - stock

Intake - LT1 modified to fit sbc
Injectors - 30 lbs/hr
Fuel pump - (do I need to upgrade the stock unit?)
Throttle body - 52mm

Cam
CompCams 08-306-8; duration 230 intake 244 exhaust; lift .510" intake, .540" exhaust ( I don't think that this would be to wild in a 396, any other thoughts?)
Lifters - stock roller

Exhaust
Headers - Hooker Long Tube SC 2210 (I'm not sure how these are going to fit with my Spohn T56 crossmember....but I'll make it work)
SLP 3" cat back

Engine management
ECM - Stock 730 with tuning through Prominator

If you think I missed anything let me know.
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Old Oct 3, 2005 | 02:36 PM
  #2  
five7kid's Avatar
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Well, 6 days, no opinions.

An opinion is about all you'll get out of me, because I've never done anything like this.

Most 396 SBCs seem to be LTx & LSx's. No particular reason for that, just seems to be the case.

Internally balanced, eh? Decent. Always like to see that.

Haven't been hearing good things about Clevite since they moved production out of the US. Federal Mogul seems to get the votes these days. Except for those who say there's nothing wrong with Clevite (the Clevites went in my 396 BBC in 1997 - no issues with them in hundreds of runs and thousands of miles).

I think I'd assume a fuel pump upgrade is in order. Aftermarket pushrods would be cheap insurance. Rings - there's an intuitive attraction to gapless, for some reason don't see them used a lot. I didn't only because of cost.

If budget would in any way allow, I think I'd go for a Motown block. Of course, might as well go with 4.125" bore while you're at it.

Hmmm, 4.125" bore, 3.875" stroke, street/strip power, mild manners, short and occasional long trip use - and the downside would be...

... additional cost.
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Old Oct 3, 2005 | 03:34 PM
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Chris90Formula's Avatar
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From: Pompton Plains, NJ
Five7, thanks for the response.

I would love to have a motwon block and make it a 427, but that would add over $2000 to the cost...too much for me.
Any thoughts on the cam and rockers?
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Old Oct 3, 2005 | 04:17 PM
  #4  
Klortho's Avatar
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From: Kingston, Tn
Car: 1987 GTA
Engine: LT1
Transmission: T56
Axle/Gears: 9 bolt 3.70 posi
Re: Opinions on my 396 build

Originally posted by Chris90Formula


Cam
CompCams 08-306-8; duration 230 intake 244 exhaust; lift .510" intake, .540" exhaust ( I don't think that this would be to wild in a 396, any other thoughts?)
Lifters - stock roller

Plus the advertised duration on this cam is 297/307 with a 112 LSA

This is the cam I'm getting ready to put into my LT1, plus if you are going to be turning the motor over fast alot Comp recommends using the 987-16 springs, however....

I found a place that has a single spring that is a direct drop in that doesn't require cutting the spring perch (at least on the stock LT1 heads, not for sure on the AFRs), and you still use the stock retainers and locks that is good for up to .600" lift for like $75 bucks which is the way I'm going to go.
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Old Oct 3, 2005 | 04:33 PM
  #5  
Lo-tec's Avatar
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From: Gambrills, Md
Car: clapped out 84Z
Engine: 355 efi roller
Transmission: tremec TKO
Might want to read this:

http://www.airflowresearch.com/artic...cle31/A-P1.htm

Same thing you're looking at doing but .060" over. Looks like an interesting combo.
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