O.k., I did some research at mortec and a few other sites getting mixed results. I just purchased a 350 (supposedly) with 4-bolt mains (I dropped the pan to verify it being a 4-bolt). I have run the casting code 3970014 and found dissimilar information at different sites. The suffix code is T0416CRE. the casting code on the head (driver's side) is 3998993. I have also found dissimilar info on these. Does anybody have reliable info about this engine? Was this engine, running or not (it does run, but smokes a little not just on startup) worth $100? I think I made a good purchase. Thanks for your help!

Mark

 

mortec.com

says the block is a 350: 70-76: 2 or 4 bolt main.

heads: 72-73, with 75 cc combustion chambers.

 

0416CRE = April 16th, 1970 found in A,F,and X body cars
3998993 = 1.72, 1.5 truck head 68-76
According to www.nastyz28.com, it was orginally a 300hp, 4bolt main, 350. Who knows what it is now.

 

So, basically the short block is good, and the heads suck? I took the pan down last night and it doesn't look like it's been messed with, but that might change when I pull the heads today.

Mark

 

The intake valves have been measured at 1.94. These are the inconsistancies I am referring to. Are these heads worth spending the money on, or should I just spend $100-$200 more dollars buying the Vortecs? I would most likely spend $350 getting these heads redone, right?

Mark

 

get the Vortecs. Even with the bother of buy a Vortec intake, they are well worth it.

You won't be dissapointed.

 

I've got a complete motor with the same#3970014 out back. Its a 350 4bolt. The heads are #3978493, I think there off a 400 small block. Would the 400 heads be anything special, what size valves did they get? I also got a # 3970010 high nickle 350 4bolt. I took it to the shop Friday to get it bored .060 and fixed for a 3.75 crank. I'm going to start taking the #3970014 apart next week and get it preped and then store it. I got both of them for free, they came out of a old Chris Craft boat that had sunk. It stayed down for a little over a week and the ship yard was taring the boat up to get ride of it , the man that owned it said if I got the motors and gears out I could have them, it saved them the trouble. I was like, Hell Ya!!!!

 

I have a pair of those same 993 heads i got of a 73 truck 010 350 motor. The heads are not that good, and i wouldn't spend any money on them, but the will flow decent if you really port them. In my opinion thought its not worth it for a performance engine. It will probably cost the same to just buy new heads either Vortec or aftermarket then to rebuild them.

 

I, too, have some '993 heads that came with 1.94/1.50 valves (stock). They are still small-port, large chamber smogger heads that would require a lot of port work to get any respectable flow. The castings also have a dual center exhaust port crossover for the heat riser and EGR. The port roofs are cast very low, and cooling passage core shift can prevent you from getting good port shapes. I was able to raise the roofs, bowl port, blend, and fit larger valves without getting too thin. You can also encounter problems in havng adequate material at the outer exhaust valve spring seats to enlarge the springs. The castings tend to just fall away in those areas, providing no base for a larger spring.

Unless you want to spend a lot of free time doing the work yourself, you might be better off starting with better castings. Once opened, mine flowed pretty well but didn't lend themselves well to low end velocity and chamber filling. Opened up, they might be good for a higher-revving engine that has to run stock castings, but not for a street car that needs torque down low.