looking to build 402

[deatonk67]

ok my truck is an original big block truck (402) should i go with that or go in a different way? need some help... how much money will i have in one if i do a complete rebuild. please give your two cents

[jjhare]

If it was me I would stick with the original. Not sure on cost, that just depends on what kind of performance you want out of it!! My $.02

[Longhorn 70]

I know that when I built the Olds in my pickup 25 years ago it cost me almost $1500 for machining, hard parts and gaskets. I don't know what that means in 2012 dollars.

Granted Olds is a bit pricier to build but BBC can cost too. It will depend on what can be salvaged and how "built" you want it.

Good luck buddy.

[toyplumbertrucks]

Hey , I built one a year ago and never used it. It cost me $2200.00 for all the machine work , parts and cleaning. Than I spent about $350.00 into finding the right brackets and pulleys and a additional 200.00 to get them and the exhaust manifolds powdercoated. Than I decided not to use the engine goes it was way to close to the firewall on my 4X4 K20. If it would of fit I would of but it in their in a minute. Well anyway it expensive, if your ineterested in one already built and never ran you could get mine for about 2200.00 without the brackets plus shipping. Depending on what you want your looking at least $2000.00 and my small block 350 crate motor from phoneix engine with 330HP cost me $2200.00 plus accessories. Hope this helps a little

[prostreetC-10]

Let's clarify: is your truck an original BBC truck AND doesn it have the correct motor or just a BBC truck? If you have a BBC truck and the motor, then you might want to rebuild the original motor just for value reasons. If you are thinking about looking for a 402 to rebuild then I'd say HAIL NO!!!! That's like looking for a 283 to rebuild when the world is full of 350s. Machine shops charge just about the same in MACHINING costs whether you are doing a 402 or a 540 (within reason). If you are going to do a true rebuild, which includes an overbore and pistons, you certainly should look for a 454 and get a much better return on your money and huge torque. Believe me...I take my own advice. I was getting ready to rebuild my 454 when I looked into the slight difference to produce a 496. Granted, I have now gone crazy with aluminum heads and what not but you get the idea. Bottom line is it's up to you but the 454 is where it's at if you are starting from scratch.

[c10srule]

built one last year for $1500 including purchase price, i the guy that does my machine work is very reasonable, around 200 for the block work and another 100 for the head work,, now my 454 was close to 500 in block work but took it to atp because of using molley rings, 2200 for machine work sounds really pricy, nothing id ever spend, i built a 454 last year also and only had 2500 in it which included a lot of goodies from summit

[derrickmanx1]

I have a built 408 and will be dynoing it today. I will let you know what it makes but it will be very close to the same cost as a 454. The stock heads make great power on them with the right cam and out flow most performance sbc heads stock. They are heavier than the sbc or ls series of engines. I just like bbc and the thought of using the old 402. My $.02

[deatonk67]

thanks for helpin guys. the truck is a true 402 truck. i can buy the motor for 300 is it worth it? or should i just go with a carbureted ls motor

[Ol Blue K20]

I put a 402 in my K20 and haven't regreted it one bit. It even gets better MPG then the 350 did

[alsriv2]

Speaking from some experience on this, I just had the original 396 completely (re)built for some good performance. It cost a small fortune as the original engine was very tired and worn. But, I had the nostalgic "keep it original" frame of mind, but ended up going wild with it. That is what cost so dang much. The end result is a 396, .060 over, a set of 402 heads, probe pistons, Lunati roller cam with roller rockers, and many other performance goodies.

For all the $$ spent, my engine shop was able to squeeze 469hp and 450 of torque around 3700 RPM out of the beast on the Dyno running pump fuel and a Holly DP750.

I have not installed it into my '69 yet, but am looking forward to this spring when it can be done in the warmth.

Given the choice to do it again, I would have gone the 454 route. probably would have cost me alot less and physically the exterior of the engine is nearly identical. My truck is a custom build, so I was not looking for originality to start with.

Good luck with your decision.

[GASoline71]

"Numbers matching" in these old trucks isn't going to get you any more cash when you try to sell it. There are no rare engine combos.

You will spend just as much, or even more to rebuild the 402, than it would to build a 454. Just something to look at. Way more TQ for the same price.

Gary

[toyplumbertrucks]

Originally Posted by c10srule

built one last year for $1500 including purchase price, i the guy that does my machine work is very reasonable, around 200 for the block work and another 100 for the head work,, now my 454 was close to 500 in block work but took it to atp because of using molley rings, 2200 for machine work sounds really pricy, nothing id ever spend, i built a 454 last year also and only had 2500 in it which included a lot of goodies from summit

c10srule just curious, how much of that engine build did the machine shop do? Was it a complete build top to bottom? Did they turn the crank, install the cam, put in the oil pump, mount the heads, put on the intake, paint the engine, and give it to you ready to go? How many of the parts were new? Was the block and heads and intake steam cleaned before the build? If so you got a great deal for $300.00.

[toyplumbertrucks]

Originally Posted by toyplumbertrucks

Hey , I built one a year ago and never used it. It cost me $2200.00 for all the machine work , parts and cleaning. Than I spent about $350.00 into finding the right brackets and pulleys and a additional 200.00 to get them and the exhaust manifolds powdercoated. Than I decided not to use the engine goes it was way to close to the firewall on my 4X4 K20. If it would of fit I would of but it in their in a minute. Well anyway it expensive, if your ineterested in one already built and never ran you could get mine for about 2200.00 without the brackets plus shipping. Depending on what you want your looking at least $2000.00 and my small block 350 crate motor from phoneix engine with 330HP cost me $2200.00 plus accessories. Hope this helps a little

Hey I just checked and Somerville isn't to far from me. I am so confident in the quality of this build I would bring it to you, for free! Let me know if your interested and I could get you some pics.

[deatonk67]

throw some pics of it on here

[1972RedNeck]

I'd stroke the 402.

[prostreetC-10]

Originally Posted by 1972RedNeck

I'd stroke the 402.

Why is that? Now you have even more money into and still don't have the power/torque if you put that same money into the 454. Heck....I'd stroke a 454......wait.......I am!

[toyplumbertrucks]

Here are some pics. I wish I could of used it. I will tell my boring story of stupidity and stuborness again. I had this engine in my C10 converted to a 4wd back in the early 1990's. It fit well. I got a factory 4wd frame and started to work on the frame and engine at the same time (about 2 years ago) without doing any research. All was going great, the engine fit into the saddle of the frame and bolted to the transmission like a dream come true.Than I lowered the cab on to the chassis, OH CRAP!!! The engine was right on the firewall with another 4" to be lowered. Well ,after walking away from the problem and thinking about it for several months , I decided to go with the small block. That is why I built the engine and spent so much emphasis on the right brackets and such, it was truely a dream turned inot a nightmare because I did not research it, and I had to have that big block. Chevy never but Big Blocks into the 4wd Trucks. Luckly the alt., starter and ac motor are the same so I used them on the small block. If you do not need these brackets I will take them off and and sell them seperate. I will not sell them seperate untill I get a definite sala on the engine. Oh, I do apololgize, after reading my 1st post it did sound like I had $2200.00 into the machine work, Sorry. $2200.00 is what I paid the machine shop to build this thing complete plus or minus a few parts (re: intake, oil pan, valve covers). Than I added the brackets and exhaust manifolds a little powder coating and other small stuff to get to a total investment of over $3200.00. Thanks, Kevin.

[toyplumbertrucks]

A few more pics:

[engineer_gregh]

Good thread. I've got a 71 Super with a 402 factory engine as well. I'm getting a lot of pinging and rattling and thought about a rebuild. My engine leaks a few drops of oil on the driveway every time its driven, I suspect from the rear main, and i'm burning a quart of oil every 500 miles or so. My suspicion is the engine has never been rebuilt and still has the original valve seats which don't work well with unleaded gas. I'm still trying to decide on going with a 454 crate engine or rebuilding the original.