402 BB question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Griz1055 · 03-12-2009, 10:44 PM

Howdy, I posted this on the main page in "engines" but haven't gotten a response. New poster, but have been reading since August. I bought a '69 4x4 last year to fix up and pull my camper. It has a nice 350, but getting up there in miles (100k). I have a newly built 402 sitting in the garage I can have if I want to keep it. I would like BB torque and power, but this engine has closed port heads and high comp pistons. I read that it is built to run all out, all the time (racing?) Just wondering if it would be a good camper puller and occasional street cruiser and mountain expolorer or is it too hi performance for what I want? Also, would I need to run above 91 octane with this set up? Here are the specs I have for it:

Melling Performance cam (22204)
cam lift .296 int .311 exh
valve lift .503 int .529 exh
L35 oval closed chamber heads 400 hp
SRP-BB high performance high compression forged pistons
Casting # 3969854
Chevy Racing manifold

Thanks! Brent

royo · 03-12-2009, 10:54 PM

its really going to be a ground pounder and what is the comp ratio. sounds like it will need racing gas

**clay68c10** · 03-12-2009, 11:06 PM

Sounds like a pretty lumpy cam. It might be ok for your usage depending on what rear gears you have. I bet you'll have to run premium with the closed chamber heads, usually they're pretty close to 9:1 with flat-tops and much higher with any kind of dome.

**68350** · 03-12-2009, 11:40 PM

Welcome from Butte, MT!! Sorry I cant help with your question.

dwaite72lnghrn · 03-14-2009, 07:52 AM

I would think the torque would be to low at the bottom end to do a good job of pulling. The cam would make good torque just to high in the rpm range to help your starts and on a hill it would bogg down and probably ping on you. JMO

Griz1055 · 03-15-2009, 12:10 AM

It sounds like it isn't going to work for what I need. Thanks for the help, everyone!
Brent

**j_cst_10** · 03-15-2009, 01:54 AM

Well, the 402 may not work for what you want it to do, but save that engine for a rainy day. Who knows, you may need a truck or car that will remove a fur tree from your property

03-12-2009, 10:44 PM	#1
Griz1055 Registered User Join Date: Dec 2008 Location: Missoula, MT Posts: 23	402 BB question Howdy, I posted this on the main page in "engines" but haven't gotten a response. New poster, but have been reading since August. I bought a '69 4x4 last year to fix up and pull my camper. It has a nice 350, but getting up there in miles (100k). I have a newly built 402 sitting in the garage I can have if I want to keep it. I would like BB torque and power, but this engine has closed port heads and high comp pistons. I read that it is built to run all out, all the time (racing?) Just wondering if it would be a good camper puller and occasional street cruiser and mountain expolorer or is it too hi performance for what I want? Also, would I need to run above 91 octane with this set up? Here are the specs I have for it: Melling Performance cam (22204) cam lift .296 int .311 exh valve lift .503 int .529 exh L35 oval closed chamber heads 400 hp SRP-BB high performance high compression forged pistons Casting # 3969854 Chevy Racing manifold Thanks! Brent

03-12-2009, 10:54 PM	#2
royo Registered User Join Date: Feb 2007 Location: knoxville tn Posts: 1,013	Re: 402 BB question its really going to be a ground pounder and what is the comp ratio. sounds like it will need racing gas __________________ nickle and dime Last edited by royo; 03-12-2009 at 10:55 PM.

03-12-2009, 11:06 PM	#3
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,935	Re: 402 BB question Sounds like a pretty lumpy cam. It might be ok for your usage depending on what rear gears you have. I bet you'll have to run premium with the closed chamber heads, usually they're pretty close to 9:1 with flat-tops and much higher with any kind of dome. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ

03-12-2009, 11:40 PM	#4
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: 402 BB question Welcome from Butte, MT!! Sorry I cant help with your question. __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

03-14-2009, 07:52 AM	#5
dwaite72lnghrn Registered User Join Date: Jun 2002 Location: central pa Posts: 1,525	Re: 402 BB question I would think the torque would be to low at the bottom end to do a good job of pulling. The cam would make good torque just to high in the rpm range to help your starts and on a hill it would bogg down and probably ping on you. JMO __________________ 72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper 72 bug(the better half's) under reconstruction 2009 HHR aqua blue 71 GMC k20 350/sm465 2009 Chevy hd3500 6.6 Victory Red crew cab dually Dave & Jeanne

03-15-2009, 12:10 AM	#6
Griz1055 Registered User Join Date: Dec 2008 Location: Missoula, MT Posts: 23	Re: 402 BB question It sounds like it isn't going to work for what I need. Thanks for the help, everyone! Brent

03-15-2009, 01:54 AM	#7
j_cst_10 Senior Member Join Date: Nov 2008 Location: Cleveland, OH Posts: 588	Re: 402 BB question Well, the 402 may not work for what you want it to do, but save that engine for a rainy day. Who knows, you may need a truck or car that will remove a fur tree from your property



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