I was just wondering if the 350 block from a '73 would sustitute for one from '70. Reason being is i have a block from a 73 lesabre, and the heads and intake from a 70 lark. I need a good reliable engine for my lark while i get the original engine done, but it's going to be a while(money"s a little tight) before i can get it worked on. I have talked to a few local mechanics who say "a block is a block. I have more confidence in the people on this board than any mechanics that i know. I would realy apreciate any info anyone would give me. Thank you in advance.
73 heads it works forward, 73 heads wont work on a 70 engine but 70 heads will work on 73 block.the scalops for antifreeze in the center of heads will hold you up. you willl see if you put them next to each other. intakes should still swap.:TU: andy
thanx Andy, would hate to have a freshly bored block that I could not use. My 70 lark has seen better days, but as a testament to Buic it has 278,000 miles and still runs great. the smoke is what drives me crazy. All the guys on the board have been a great help to me and have made me a life long buick fan. thanx again.
I have a '78 block with '69 heads in my '71 now. The differences between my original 71 and 78 block were: more webbing on the 78 block at the rear, both inside and out. Also no provisions for a windage tray. I also had the issues with the scallops, but didnt have to worry 'bout it with the '69 heads I used. One thing to check for on later model blocks tho, CASTING POROSITY!! The oil passage going from the main oil galley to the rear main bearing leaked like a firehose :shock: I cant believe I drove this car over 1200 miles to and from the Nats a few weeks earlier in 90 plus degree heat and the oil pressure never droped below 18 lbs at hot idle. I never would have thought to check for porosity in the oiling passages, I think as the molds got older things got a bit sloppier. Just something to consider if you have the engine out and apart. Mark
71heads 71 heads should work on 69 block but you wil have to plug the oil port to head for oiling rockers and use 70 and up lifters,rockers and pushrod unless someone knows a different way to oil rockers. but should be no problem.change year is 72 for scallop .its like a midyear change. andy:TU:
Re: 71heads Thanks Andy, Thats the info. I was locking for. You mention 69 block, but Im asking -68! I assume there is no difference between those two years? o No: Lars
later heads will work fine. you just have to plug the middle coolant passages are the egr holes if using an earlier intake. i plugged mine with some regular freeze plugs, coated in epoxy, after i bored the holes out a bit with my dremel. this was the advice of jim burek, who said he has also done this with no problems...i found it to be pretty easy and i have had no issues.
Thanks for the info! Now I can keep on planning the head port job, and know that I have a useable set of spare heads! (If something fails) Don, sorry I crashed in on your tread, but your question was of the same kindbut different! :bglasses: Lars :Comp:
no problem. The more info i can put in my head the better. Good luck, and let me know how it turns out.
