any engine builders out there?

[truckincurt]

was wondering what would be stronger a 78 4 bolt 350 or 83 4 bolt HD motor... dont have casting numbers yet havent had time to wire brush the 2 motors i know the older the motor the stronger but the newer motor being a HD idk what block is stronger ? thanks guys

[CreditGod]

My dad has been building motors for 40 years now mostly high performance
so if it is going to be a performance motor i would use the 1978 it does not mater if it is 4 bolt main or to bolt main until you start reaching 550 horse power straight motor or if you are rapping high rpms like 10,000

now if it is going to be a daily driver then save the 1978 for a project down the road.

[chevybuldr]

I have seen all kinds of motors especially chevys. I have sonic checked and magged alot also. To tell you the truth it doesnt matter when it was made. Seen the early ones 010 020 crack and be thin between the cylinders. Now dont get me wrong I would take a 70 motor over an 80s-90s block anyday. 010 have the better nickle content. The later motors were getting cheap and thin. So what would I do? I would find out which is a 4 bolt. Then I would find out if the been rebuilt before. Then I would pick one and take it in and have it cleaned, magged and sonic checked. Chevys I have noticed are thin between the cylinders. Cause for an over heating problem. Post some pics of the valleys of the motors. Maybe we can see somthing before you go thru the trouble.

[1968SWBBigBlock]

Agree with some of the comments above - look the motors over - has one been better taken care of - if so it is most likley your best option.
A pressure check on the block might force you to choose one over the other never know.
I can remember when no one would use a mid 70's block - we thought they where junk - to thin - cheap metal - now we look for them because they are better than many of the later model blocks -

[truckincurt]

there both 4 bolt motors.... i know complete history of the 83 motor the onley thing i know about the 78 is that it has a cam and that its so tired lets just say that i ran it at the local 1/8 drag strip lancaster ny and it took me 13.872's to get down the 1/8 mile ....talked to my machine shop a few weeks ago before i bought the newer motor he said with the componets i wanted to use i would be making around 550 FT lbs and arond 500 horse not to bad for a n/a motor haha .... with that i think im goin to blow up my tiny 10 bolt that has a 100,000 miles on it lol but dont have the money to get a 12 bolt anywho ill take pics of the vally on the 83 tomarrow dont realy want to take the 78 apart its my onley vehical for the next week to i get the bonnivile done for my mom then ill get my car back thanks alot for everyones help!!!!

[Alex1]

I would pick the engine that has the least wear. As for your 10 bolt, I think they're running 8's in the quarter with them properly built. A truck 12 bolt is about as strong as a 10 bolt - same pinion shaft diameter.