I had planned on stroking my 1985 Vette to 383 w/Scat 9000 crank, & stock 5.7 rods and D-port heads.
I can pick up a 2-bolt main, casting #3951509 standard bore 400 block with some wear, for $225 for the block, crank, and 5.565 rods and bore it to 406. I could have the 400 splayed I guess if necessary.
Will the distributor, and damper etc swap out from my 350 to the 406? Any major issues?
Intake, cam and headers and 113 D-port heads with 2.0 & 1.6 valves would all be equal being a Stealth Ram preferably after making my own plenum or a Superram. At the least a major port job on the stock plenum and large tube runners and a new base.
I m not building a monster thumper but would like a potent ride!
High 12's or very low 13.s
Help me before I go crazy, this thinking so much about how to build this motor is making me nutso!
The chevy sb 400 crank uses very different damper and very different flywheel/flexplate ... they do not interchange with what came on any other motor ... they'll bolt up but an engine-destroying imbalance will result. I've heard there are Scat9K 383 cranks that are designed for internal balance ... thus can use 350 damper & flex/fly ... however, such cranks would be the exception. Most Scat9K 383 cranks are external balance (just like sb 400 is from GM) and require the 400 type damper & flex/fly. More importantly, chevy 400 blocks & cranks have a main bearing that's larger than 350 ... so you probably wouldn't want a 383 crank anyway. Scat & others have a 3.75" stroke crank made for a 400. Whatever used rods you choose, do change out rod bolts to ARP or SPS and have rods resized. The short rods'll work fine but have some limitations ... suggest 5.7" or longer. The distributors do interchange. Many times, performance strokers have cam-to-rod clearance issues ... that possibility must be taken into consideration. This ain't rocket science ... but there's more to it than a rebuild.
There are crank & rod options that may pay dividends upon assembly & use. Also, it would be prudent to have your local machine shop pro perform a close inspection of the 400 block before you proceed. Have you planned a budget? ... and what is intended use & goal?
You will get many opinions and a diversity of answers. My thoughts on this subject have long been: For the same or only slightly more money, why would a guy cut .200" off his main bearings and give up an 1/8th inch of bore to build an engine with 20 or so, FEWER, cubic inches? For a specific class or another definite purpose, OK, but otherwise it doesn't make sense to me. Go for the cubes. If you bore, you will have to buy pistons. Get pistons for the 5.7" rods you already own (in the 350). They won't cost any more. The money you spend on the block, will come from the crank you don't have to buy. Some things you should do to build a 406 include having the steam holes drilled in your heads. Some have skipped this step and gotten along fine, But since it is apart... As Jackson stated above, you'll need the 400 damper and flywheel/flexplate as you would for MOST 383 conversions, so that isn't any additional cost. In the 400, only, the 2 bolt block is the prefered block. Don't go nuts and let anyone talk you into having 4 bolt caps installed. They are stronger this way, but for what you are describing, you DON'T need them. There are plenty of people on here that will spend your money for you, but if you stick to the "KISS" principle, and take a straight forward approach, you will end up with a "thumper" that will excede your expectations.
"The only substitute for cubic inches is rectangular dollars."
I agree my thoughts are really related to the piston side loading on a stroker. I would like for the engine to last as long as possible.
The 383 and the 400 (406) use the same stroke crank. The origional 383's were built with 400 cranks that had the main journals turned down to fit a 350 block. Between the two choices you are considering, there is NO difference in side loading.
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I agree, the cost for the 383 crank is what I can pay for whole block and crank. I thin the 406 built moderatley would make me a happy camper.
I think may just go slow, check the junkyards and build a 406!
That 400 you said you found in your opening post sounds ideal. It's reasonably priced, too.
I suggest getting another 400 for the following reasons:
I checked with a local machinist for prices: Rebuild 350 = $1500; Rebuild 400 = $1800 because pistons are a little more; convert 350 to 383 = $2500 because everything has to be machined, assembled, checked, disassembled, machined and checked again. Plus there is the danger of ruining the block when clearancing it.
I called one junkyard and he had a complete running 400 for $300.
So for less money you get more motor. You make the call.
BTW, 5.7" rods are cheap, a full set would be under $200, so you wouldn't have to steal parts off your 350, but the big ends have to be ground to fit (whether going in a 383 or 400). Since the 5.65" rods lasted over 100,000 miles in station wagons, what's wrong with using them? I had a stock rod 406 in my street rod and turned it to 5800-6000 all the time. Make sure you have the motor balanced, and use ARP rod bolts.
Have fun!
Joe
PS don;t post on a pontiac board that GTOs were big blocks, they get sensitive about that LOL. :lol:
I was going to go 383,but the machinist talked me out of it.The only difference in cost is the block,and you end up with 23 cubes more motor. It swayed my decision to the 406. As with everything else,once you decide,you wonder what if you'd gone the other way.Concidering the extra 30-50hp,a couple hundred for the block was nothing.
Corvette Store
Build a 383 or 406?
