pulled from mid 70's big boat , lesabre i think . it was heading for the derby , dave uses SBM motors . i think '75 ? i just want to confirm as much as possible before going next few steps . not that it should be hugely different from the '69 block i did , in car now . i'm using matching block , crank , rods . other parts i've gathered and saved last few years . numbers - left rear of block where it angles out sez : 350-1 behind intake , above bellhousing are : GM X 5 124 748 and there's a "clock" cast in also , thats all i can see . i checked the pad areas below the corner cylinders but did not see any markings after cleaning them off ? --------------------------- crank is set - mag'd , turned 10/10 , casting crap smoothed down rods have been checked and mag'd . i'm working on the beams now - give 'em a quick smooth n polish working on block now , cleaning , smoothing lifter drain area , removing plugs , cam bearings etc . ---------------------------- thanks for any info
Just keep in mind that the 75 heads won’t fit on the 69 block because of the extra coolant passages. That’s a 72-80 block. The head casting number is under the valve covers.
'75 ( or whatever ) block . the '69 motor is in the '65 now . this is a different motor . older heads , 70 i think , i'll list those head #'s later . not a bad idea probably to dbl check . especially since i've got a set of TA 1.6 roller rockers to install . pushrod oiling required . ----------------------------------- main bearings and cam bearings out just now , not beat up looking , alot of copper showing though . rear cam oil galley NPT plugs are being a pain .
Head numbers : Both numbered #B1233472 One head stamped with 1 , 70 , F30 Other head stamped with 4 , 70 , F30
opinions : #1 - oem cap screw rods , mag'd , polished beams a little , have ARP bolts for 'em . need prepping , ARP head seats need to be "leveled" and small end sized for floating pins . ( AMP diamond pistons ) or #2 - sell the oem rods and ARP bolts and order TA $600 rods ? less prep involved , looking like $200 dif i think ? i guess my question is , how much better are the TA rods compared to the oem cap screw style rods . budget ( and common sense ) will limit me to these two choices . mmmmmmm - aluminum rods . uh - no . face slap emoji !
Hi, if you aren’t using a power adder then the stock rods with ARP are fine. If you think you may add boost or nitrous then use the better rods. I wouldn’t use alum rods on a 350 as there isn’t enough clearance between the camshaft and the big end of the rod shoulders, I looked into this heavily.
yeah , TA advised me to be careful with clearance on the big end . ----------------------------- edit - ran into dave today , said car was a '76 . so block crank n rods should be '76 probably . no real dif as far as parts or setup but good to know . checked with a couple machine shop guys locally that i've worked with before . both seem to do careful work , busy , pricing was about same either way .
OEM cap screw rods are safe to 6000 rpm, but like Sean mentioned if your going to wing it past 6 grand use forged rods. Excessive RPM takes out rods.
the oem rods are gonne be : beams polished , ARP bolts , lightweight pistons , balanced . probably ok . still thinkin' though - like the "insurance" . appreciate all the info - too much junk in the brain .
Without a power adder the factory rods with arp are plenty. Just compare the cost vs forged, it’s not much different after ARP and re sizing
I didn't know anyone that spun the motor past 6 grand and it went "poof" Only the SP3 is going to let the engine go past 6 grand so use the TA S/P and you will be ok. you want to spin it to 7 grand yeah you probably need the light pistons and the better rods. That is what I would do if I knew I was going to 7 grand. I have spun to 6200 a bunch and hit rev limiter on nitrous so I would say we good. I wouldn't worry about it too much the engine is pretty damn tough.
