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Discussion Starter · #1 ·
i have a Gen 1 350 4-bolt main and want to put an eagle 383 rotating assembly in it to make it a stoker...the kit has flat top pistons...5.7 rod length...and the 383 steel crank....ive heard a few different things about trying to put these kits in....ive heard from some people that you have to file down some of the rods and the block webbing soo that they dont hit.........is this true???? ive also heard that rod caps might possibly hit the stock oil pan.....is that true??? ive also heard u can have problems with parts hitting each other depending upon the camshaft that you use.....is that true???? if any of these things are true and i do infact need to modify my block or parts....how would i go about doing that???.....is it something a beginner could probably do at home or does this require precise machine work???....i need to know for sure soo i can figure out if i want to go the stroker route or not...soo any answers or info on this rumor would help me out....
 

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It's All True,........... To a Point,+ Depending on other Points.........

And,...... No.......
It's Not for Backyarders...... Muchless a Newbie Backyarder.......
 

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Yes, you will likely have to do some block grinding for things to fit. The parts you pick and the block your using all affect how much and where. The cast steel cranks tend to need the most room to clear the block, while the more expensive 4340 forged stroker cranks seem to fit more easily (less grinding). I have found 1 scat cast steel 383 crank that had counterweights so big there was no way it would fit and still have enough block left to be safe. This was early on in the cast stroker crank days and this seems to have been taken care of as I haven't seen one this bad since.

There are 4 main areas that usually hit, 3 on the block (easy to fix with a die grinder) and the rods and cam on certian cylinders(not so easy..Need different rods and/or cam).

First the block: See attached photo.
1. Oil pan rail. Usually no magic here. Put some bearing inserts in the block and lay the crank in and start turning it SLOWLY and carefully. If it hits somewhere find it and mark it. Look and see if you can remove the material needed to make it go. This is an operation where you want to measure twice and cut once!! Get the crank turning by itself so there is ~.060" room between it and the block then add the rods. You need to actually assemble them with bearings and tighten them, though you don't have to torque them. The pistons also need to be installed to keep the rods where they will be when the engine is running but leave the rings off so its easier to turn and you dont scratch them. You need to be careful to clean everything really well between grinding sessions and fitting things up or you'll scratch the crap out of your bearing surfaces. I use a set of bearing just for this and don't use them when you do final assembly as no matter how careful you are there will be some grinding material embeded in them that you dont want in a running engine.


2. Outside cylinder wall. The rod bolts hit here. Fix this the same way as same as above. Rotate the crank see where things hit and remove that material. You don't have to have all the rods on at the same time but you do have to check EVERY cylinder. If you haven't assigned the rods a home now's the time as they should stay in the cylinder they were checked in. Also don't put one rod on the crank and tighten it as this can damage the rod. They must always go on in pairs so that they are supported against the side load tightening the bolts causes. IMPORTANT! In this part of the block there is a water jacket above the material you're removing! Watch how close you're getting to it. The freeze plugs should be out, this will allow you to see where it starts.

3. Inside cylinder wall. Another area where the rods can contact the block. Usually don't have to remove much here and there aren't any water jackets near here.

4. Once the crank and rods/rod bolts clear the block you have to instal the cam and timing chain. Line up the timming marks as if your putting it together for real as the position of the cam in relation to the crank will effect what clears and what doesn't. All of the rods need to be installed for this. SSLLOOWWLLYY rotate the crank to see if it clears. If you do this too fast and a rod bolt hits the cam it WILL nick the face of the lobe and your cam will be junk! If everything clears with at least .060" your set. Time to start putting it together for real.
If it hits you have a problem, the only safe way to fix this is to use different rods or cam. There are people who grind away the rod bolts to get clearence. In my book this is asking for trouble. Rod bolts are some of the most highly stressed parts of an engine, not the place for shortcuts.

The block in the picture is an '89 350 block cleared for an Eagle 4340 3.75" crank and 5.7" 4340 H-beam rods.

Hope this helps and good luck!
 

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Just wondering how many times you're going to ask these same questions???? Yesterday at 3:00 pm you asked about the oil pan and was told its not a problem and was given the reasons why. Now you are asking the same question. If you don't believe us then don't ask. You need to get a good engine building book on how to build a small block chevy....and READ it.
 

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Discussion Starter · #5 ·
that sounds real complicated....seeing as how this is my first engine.....do u think i should go for it.....i really dont have much exp... in block grinding but....i would really like to have a 383....also....is it almost for sure to hit in those places or does it just depend on the engine and rods???.....is it really all that hard to do....or is it just as easy as you make it sound???
 

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350rebuilder said:
that sounds real complicated....seeing as how this is my first engine.....do u think i should go for it.....
Only you can answer that.

Do you have the tools and time to do it yourself?
How mechanically inclined are you?

If you screw it up would it be the end of the world to you or would you say "that sucks..guess I need to find another block..I really wanted a 400 anyway."

There was a time when everyone had no experience. If you want to build fast cars you either need a fat wallet or you have to try things yourself. Sometimes it doesn't work and you screw something up. If your the kind of person who would beat themselves up forever over it you need to get rich, make friends that will do it for you, or find another hobby.

I can only laugh when I think about all the stuff I've screwed up or blown up.



It's all up to you.
 

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Why not just take your block and rotating assembly to trusted machine shop where this is all second nature to them and you have a far less chance of messing things up. My guy did my 305 to 334 stroker for $350; fitting and grinding the block and assembling the short block. I know $ may be a concern but if you mess it up you have to start over and that's more $. At leat have them do the fitment and you can do the assembly. That's just my opinion but what do I know. BUTCH.
 
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