i have a complete 350 needs a complete rebuild. looked at a place in redding and they want $1200 for a stock 350 comes with a 12 month warranty. option two is to build one with my buddy for about half that. option 3 is to build a 383 for about $800. just got my PAW book and the prices are pretty resonable. my buddy is a heavy equipment mechanic and myself once the cam, crank, and pistons are in i'm good to go. so what do you guys think.

time and money are not an issue:)

the vehicle it's going in is a 70 fj40 with turbo 350 np203 dana 44 front 12 bolt rear. want an all around wheeler

383. check out Summits prices though.

What are you putting it in and what are you going to use it for? I built a 383 for a half ton Chevy back in the mid 80's and it was one of the best engines I ever had. Had a lot more torque when towing my travel trailer than the original 350 had. If your putting it in something light weight and only using it for rock crawling I'm not sure you'll see much benefit. The prices you're talking are way reasonable though, so if time and money aren't a problem as you say I'd probably go with the 383 just because!

383 all the way i did. has more torq. you can when building it, using the right came decide when and where (rpms)your torq and hp are. that is the benifit of building.

just buy the manufactured 400/383 crank, don't grind its just not worth your time and money.

jeff:usa:

377 or 400. Personally I don't see why you would waste your time on a 383, 400 blocks really arent that hard to find. Build a 377 and get the benifits of long rod and bigger displacment then 350. I first hated 383's because they were trendy, then realized they have a poor Rod/stroke ratio, the small bore shrouds the valves (bad for airflow mmmka) also more stroke means more friction. Just my opinions, I'm no expert but have done some daydreaming about it.

if time and money are not an issue i would build a 406. my personal favorite. just my .02 :D

Is the 383 already complete, and just needs to be rebuilt? If not, I would sure like to know where 800 bucks comes in. If you are looking in PAW for a stroker kit, you can plan on spending a bunch more money than that to build it from a stock 350. Try looking at northernautoparts.com for kits for a 350. They are more reasonable than PAW.

IF YOU ALREADY HAVE A MOTOR.......ASSUMING ITS IN GOOD CONDITION......I WOULD HONE IT RERING IT NEW BEARINGS ,GET THE HEADS DONE,ALL STOCK WITH A MILD CAM,,YOU CAN DO ALL THAT FOR UNDER 500$$$$$$$

SPEND THE EXTRA MONEY ON FUEL INJECTION,TPI OR TBI...
PICK UP A COMPLETE SETUP FOR ABOUT 700 AT THE MOST.....EASY INSTALATION TOO...IF YA GET STUFF FROM THE RIGHT PLACE..........

502 baby!!! :D:D

IronPig70 - I would go with the 383. They can be a bit more to build, but the torque difference is noticeable from a mild 350.

BTW - which shop in Redding? Are you up here too?

Enough research has been done to show that if you'd take the $$$ needed to convert a 350 to a 383, and instead spend it on go-fast stuff for the 350, you'd be better off keeping the 350. Now, there's no doubt that there is no replacement for displacement, and all things being equal, the 383 will make more power. But, it'll cost more. For the same $$$, you can build a 406 & have even MORE cubes. Basically, the only purpose of a 383 IMO is for guys who WANT a 400, but already have a good 350 block laying around they want to use.

As said before, if you go this route, buy a crank that's MADE for this purpose rather than milling a stock 400 crank. (BTW, GM makes a 383 cid "crate" engine. This is not the traditional "383" in that it uses the STOCK 4" bore of the 350 with a 3.8" crank instead of 3.75". That crank can be purchased separately hint, hint).

TEX

Originally posted by TEX
Enough research has been done to show that if you'd take the $$$ needed to convert a 350 to a 383, and instead spend it on go-fast stuff for the 350, you'd be better off keeping the 350. Now, there's no doubt that there is no replacement for displacement, and all things being equal, the 383 will make more power. But, it'll cost more. For the same $$$, you can build a 406 & have even MORE cubes. Basically, the only purpose of a 383 IMO is for guys who WANT a 400, but already have a good 350 block laying around they want to use.

As said before, if you go this route, buy a crank that's MADE for this purpose rather than milling a stock 400 crank. (BTW, GM makes a 383 cid "crate" engine. This is not the traditional "383" in that it uses the STOCK 4" bore of the 350 with a 3.8" crank instead of 3.75". That crank can be purchased separately hint, hint).

TEX

Tex,
What do you have to do to a stock 400 crank to use it in a 400? I thought you just dropped it in there and used either 400 rods or pistons with a high wristpin. You also have to use a 400 balancer and flywheel. Am I missing something else?

If your 350 rebuild is going to require you to buy a new crank and/or rods anyway, then I'd say the 383 option sounds good.

Originally posted by Grandpa Jeep


Tex,
What do you have to do to a stock 400 crank to use it in a 400?

I think what you meant was "what has to be done to a 400 crank to use in a 350 block?" If that's what you meant, the answer is:

Mill .200 off the mains.

TEX

Thanks Tex, that is what I meant. I didn't realize the mains were different. Do all 400s have larger mains? I used to work for a guy who ran a stock car. He originally built a long rod 406 for it, but it had too much torque coming off the corners. He rebuilt it using a 327 crank and even longer rods. It cut down the torque coming off the corner and gave him more top end down the straightaway. Didn't think he modified the mains at all. I'll have to ask how he did that.

i think we all agree that torque is the name of the game.

I am dreaming of a 6" rod 350. These have increadibly flat torque curves. I think they used Olds "Rocket" motor rods but they are producing them now adays.

9:1 compression, a well selected cam, bolt on a set of good 1.94 heads, dual plane manifold and FI and that is a tourquer, IMHO

I think that combo would have enuff muscle in the mud, spin out well for the sand, enuff grunt for rocks and still be fun and cheap to repair.

Originally posted by Grandpa Jeep
Do all 400s have larger mains?

Yup.

I used to work for a guy who ran a stock car. He originally built a long rod 406 for it, but it had too much torque coming off the corners. He rebuilt it using a 327 crank and even longer rods. It cut down the torque coming off the corner and gave him more top end down the straightaway. Didn't think he modified the mains at all. I'll have to ask how he did that.

For a large-journal 327 crank (or a 350 crank for that matter), you use spacer bearings when destroking the 400. BTW, that 3.25" crank in a 4.155" bore (400 .030 over) gives you a 358" displacement & this is the same formula used with NASCAR engines. The extremely good rod/stroke ratio that results (usually using rods LONGER than 6") nets fantastic HP/Cube.

There's also a way to use a small-journal 327 crank in a 400, but I'm not sure what all that entails.

TEX

Thanks TEX, that clears everything up.

Originally posted by SCRAPER
if time and money are not an issue i would build a 406. my personal favorite. just my .02 :D


I second that motion. More usable low end torque and still good on the top end.