Hey everyone, I have been looking at 383 stroker kits and have some questions. I see them with the 3.750 stroke crank and standard 5.7 rods. I also see them with 3.750 crank and 6 inch rods.

I don't want to spend a ton of money this is going in my 67 vert which is not going to get driven hard ( well maybe a run threw the gears every now and then) will never be on the track or anything like that. I want to eventually put a TKO 5-speed behind it. I have a 69 350 4 bolt block Im using for the foundation and 69 double hump 2.02 heads on top with a 69 Z aluminum intake. I will probably be running 3:31 gears. This is all I have for now. I dont know what cam to use either. I am thinking I should stay in the 9's on the compretion ratio so I can run on cheap(if we can even call it that anymore) pump gas.

Which crank and rod combo should I go with? and why? Any advice on anything else on this build would be greatly appreciated!!!!!! Thanks in advance!

I see you missed the 5.565" rod 383 kits!

You can use stock 400 rods and crank and stock 350 pistons!!

pdq67

If you got the 5.7 rods already go with them and buy pistons. They will run real nice, better then the 400 rods. 6 inchers are best but more money.

You can do the stroker with either the 5.7" or the 6" rods.
Most of the internal balance cranks are made for 6" rods tho. The counterwieghts are bigger, and they need the clearance.
Pistons for 6" rod strokers are tiny lil things, the pin bore goes right thruough the oil ring groove.

For a street only medium power car, an external balance 5.7" rod setup will work fine, and that might be the least expensive way, but... external balance flywheels are not real common, particularly if you're using a 10.5" clutch and straight bolt starter and small bell. If you have all these parts all ready, it would be cheaper to build an internal balance engine than to replace them all.

That's why I mentioned the stock, 400 rod kits here!

pdq67

IMHO a 'claimer' kit from nearly all performance suppliers in your 350 block would be a good choice.
I love strokers!! I am currently building an 88 roller block from an 88 cop car. If I reused my dbl humps, that were ported and polished, and internally balanced 6"rod and an XR278HR cam from Comp that would be a great combo. REALLY torky. You can set up the heads for 62cc, leave the pistons 25 in the hole and use a cometic .020 gasket and the quench combined with the chamber design would be awsome flame travel and combustion and using stock pistons would be around 9.5:1. That would be fun driving!!
Im gonna go with higher flowing heads and ALOT bigger cam cause I like to drive to the track once in awhile. When Im done with the motor, Ill bug someoff these guys for ideas on building my own 'Cal-tracs' of 'lakewoods' traction bars. :D Good Luck!!

It would be easier and better to stay internally balanced. It's makes for a smoother running engine and flywheels are easier to obtain. The kit linked is an internal balance cast/hyper -18cc D-shaped piston 383 kit that will be about 9.5:1 compression with 64cc heads. IMO, it is the best kit for your needs at the best price.

http://store.summitracing.com/partdetail.asp?part=ESP%2D13054030&autoview=sku (http://store.summitracing.com/partdetail.asp?part=ESP%2D13054030&autoview=sku)

1st. You do not want 5.565" rods from a 400. It will cost more to recondition a 30 year old set of rods than it would to buy new good rods.

5.7" rods are a good choice in your situation. Virtually all the new 3.75" stroke cranks can be internally balanced with a 5.7" rod and matching piston -- it used to be that you could only internally balance with a 6" rod, that is not true any more. The 6" rod requires a piston that uses a spacer in the oil ring package because the piston pin is in the oil ring pack. The spacers are reliable but a pain.

I would look at a Scat 9000 series cast crank, Scat 5.7" long I beam rod, and a Speed Pro hypereutectic piston. Again, get it internally balanced. I like the SPeed Pros over the KB hyperutectic pistons because the KB require a special large top compression ring gap and have a thin (fragile) upper ring land.

For a cam, take a look at the GM hot cam. It's a hydraulic roller 218/228 @ .050 on a 112* LSA. If you want something more aggressive with the cam there are some other good choices that are 230* 'ish at .050.

Hope that helps.

Since the pistons on 6.0 rod are shorter they are also lighter and the increase weight on the rod was only 25 grams difference for me. My piston only weighs 348 grams. That makes for a pretty light rotating assembly.

Stock 400 rods are fine!!

Not the best but will still do fine! And forged 350 pistons are plentiful AND inexpensive too!

Seem's I recall that you can pick up reworked stock 400 rods cheap from someplace, but where, I forget, would have to do a 20 minute search??

PAW??? S-O-M??

pdq67

The 6" rod requires a piston that uses a spacer in the oil ring package because the piston pin is in the oil ring pack. The spacers are reliable but a pain.



We use the Mahle pistons with the MM ring pack and no spacer rings!!

What's the pain about ring spacers???

Ah, interesting. About time someone made a piston for a 6" rod that didn't need spacers. How high is the top ring land Carl? Are the rings very close together? What is an "MM ring pack" (is it a .043mm setup?)

Curious what part number for a 4.155" bore. That may be my next piston -- I plan on a refresh next winter.

What's a pain about them? Maybe I'm lazy, but I just don't like screwing with the extra part.

WOW! This is exactly what I was looking for, several views/angles and opinions. Let me say first I appreciate each and every one and thank you! I still have some questions about all of this and some things that are set in stone and that I have to plan the build off of. I have a very limited budget to work with right now.

I stated in my first post I was installing this in my 67 vert along with a tremec 5-speed ( muncie for now as I cant afford the TKO right now) and a 12 bolt 3:31 posi. I need to also say that this motor will find its way in my 69 Z in a few years. The end goal for it is to be my play motor for the 69 Z. The 69 is so far out on being restored (a rolling shell at the moment) that I don't even want to think about it. I have all my born with components except smog and yh wheels. Yes, my original dz motor ,trans, rear, everything! My original motor will never be back in the car as long as I own it. I will keep it bagged and on the stand.

So, I have to have the motor from the outside looking exactly like a original 302 for show purposes etc. the twin to my original, 186 heads, 472 intake, holley 4053 carb etc. But on the inside I want to have a street friendly motor with lots of torq and something my wife can drive in the 67, we will see about her driving the 69. Also the 67 is a running car now 327/210 powerglide and the 383 and manual trans will be a quick and relatively easy swap.

OK, I would have to say to run the original looking Z balancer (1107?)and flywheel, 403 bell and starter I am going to have to go with an internally balanced motor-- Correct?? So I am committed on that.

I want to eventually(maybe next summer)run the tremec 5-speed behind it in the 67 and I know that that requires the 621 bell and 11" clutch and flywheel setup. So I will run this setup now with the 383 and the muncie so when I switch to the tremec all I need is the trans and shifter and cross member. Am I still OK here so far??? Keep in mind later ( a few years) I will be going back to a 10.5" clutch and 403 bell for the 69 Z. Still OK??

Man I'm sorry everyone, I know this is getting long and I'm not done yet. I have been over this a million times in my head and just wanted to to get all the input from everyone here has to offer with more knowledge than myself before I start buying parts.

I have a 010 block, 186 heads, 472 intake, 4053 carb all dated within a few days of my original Z components.

I have NO internals yet, crank, rods, pistons, cam etc. So I'm thinking I should buy one of the complete rotating assembly's as a package?? Maybe the one that Eric or Ray mentioned above??

pdq67, I totally missed the 400 stuff, I didn't even know you could do that, Thanks!

Harley, can you please explain what you mean by a "claimer" kit? Thanks!

Also JimM I would like your input(anyone else for that matter) on that whole starter flywheel mess I have going on.

OK, For everyone that has posted and is still willing to stay with me on this THANK YOU!

Also what about bore size? Is this relevant to the 383 cu.in.?

So, I have to have the motor from the outside looking exactly like a original 302 for show purposes etc. the twin to my original, 186 heads, 472 intake, holley 4053 carb etc. But on the inside I want to have a street friendly motor with lots of torq and something my wife can drive in the 67, we will see about her driving the 69. Also the 67 is a running car now 327/210 powerglide and the 383 and manual trans will be a quick and relatively easy swap.

OK, I would have to say to run the original looking Z balancer (1107?)and flywheel, 403 bell and starter I am going to have to go with an internally balanced motor-- Correct?? So I am committed on that.

Yes, go internal balance and it will look original on the outside. All stock stuff will work.



I have a 010 block, 186 heads, 472 intake, 4053 carb all dated within a few days of my original Z components.

I have NO internals yet, crank, rods, pistons, cam etc. So I'm thinking I should buy one of the complete rotating assembly's as a package??

It's easier to buy as a kit. Most of the time it's cheaper and the components balance out good with each other. The kits will come with either KB or speed pro hypers. I've seen some kits where you can upgrade to a forged piston but I don't think you need that.

Some people don't like KB pistons but I have ran a bunch of them. As long as the directions for ring gaps is followed, they work great.

Yes, go internal balance and it will look original on the outside. All stock stuff will work.





It's easier to buy as a kit. Most of the time it's cheaper and the components balance out good with each other. The kits will come with either KB or speed pro hypers. I've seen some kits where you can upgrade to a forged piston but I don't think you need that.

Some people don't like KB pistons but I have ran a bunch of them. As long as the directions for ring gaps is followed, they work great.

Thanks Ray! Do you still feel like the kit you linked me to above is a good choice given all the info now? Will I be OK with both styles of bellhousings and clutches(403/10.5" and 621/11")??

Thanks Ray! Do you still feel like the kit you linked me to above is a good choice given all the info now? Will I be OK with both styles of bellhousings and clutches(403/10.5" and 621/11")??


Yes I do. If it were me building, that is the kit I would go with. I'm not familiar with bellhousings and clutches but if they are for internal balance engines, I don't see why it won't work. I'm sure someone else will chime in soon on that aspect.

You will need two starters or one w/ both straight and staggered bolt patterns for big and little stuff.

My early '80's 406 still has stock 400 rods in it and I've taken her above 6,000 rpm more than several times fine.

pdq67

You will need two starters or one w/ both straight and staggered bolt patterns for big and little stuff.

My early '80's 406 still has stock 400 rods in it and I've taken her above 6,000 rpm more than several times fine.

pdq67



Paul, I know you keep harping on the stock 400 rods. I've built 383's that way in the past. The problem here with it is the cost of getting it to be internally balanced. Since the 400 is an external balance deal, without using a longer rod, mallory would have to be added to the counterweights of the crank. Mallory is not cheap. It's cheaper to use a crank set up for internal balance from the start.

You can use a normal neutral balance flywheel, any size you would like, with the internal balance stroker.

Again, 400 rods SUCK. They are 30 year old metal and cost as much to recondition as good NEW 5.7 or 6" rods. They were the only choice back when people started building 383's with 350 pistons and turned down 400 cranks. There are SO MANY better choices these days -- especially if one is starting from scratch. Not sure why you keep goin' there PDQ.

Thanks for all the info guys!! As I stated earlier I have no internals yet, including 400 stuff and although my budget is tight, I would like to buy some new parts for this area of the engine. I believe I will go with the kit Ray suggested above.

Another question-- Will my cam choice be greatly affected between the the muncie 4-speed and the tremec 5-speed? Any other thoughts on cam choice other than the one listed above?

Once again, cant thank everyone enough for the advice/input!