You getting a lot of practice hanging that intake. I got a couple questions.The head with pinned repair (stitching). Is it on side with oil issue?.The stock pins that locate iron manifold. + sto. iron manifold has that combination. Been dupliicated yet.. I have cleaned a few B4B. For local Buick guy + mounting holes are always elongated so bolts don't hold alum. Intake from sealing.Also stock pins do not fit that tight on stock intake.Why keep installing intake using same procedure that failed allrrady- try something. Different. And we will all learn.
IIRC, I don't even have the dowel pins, haven't for years, no issues. I think those are mostly for the assembly line workers.
Ok finally got a leak down tester and tested all cylinders. sure enough the 2 (#4&6) cylinders that keep oil fouling are the highest leak percentage. Removed valve covers and air was being heard through the pushrod holes into the crankcase. here are the leak percentages in firing order at 90PSI into the cylinder #1 = 9% #8 = 10% #4 = a whopping 58% #3 = 14% #6 = 18% #5 =8% #7 =12% #2 =9% Im assuming this means my rings are shot? or cylinder walls scored badly? i understand its an old original bottom end and getting tired but is it common for this to happen all of a sudden like this? or could something have happened during the intake swap that may have damaged them? what do you guys think? next step is probably pull the motor huh
Yes probably may have a broken ring. Unless something fell into the intake during removal. Could pull the head first. Did you try a compression test also just to see if it can hold at all?
That's what I was thinking - Just read your subsequent post on when the heads were done too. I think you may have "found" your problem.
I'm pulling the head next and see what i find. If it ends up being a bad head i do have a spare set and will have it rebuilt. If the bottom end needs to be rebuilt im not sure what i should do. I have a buddy that has a good running HEI 455 (guessing 74-75) that he wants $600 for. If the 350 has to come out these will be my 2 options, spend the time and money on rebuilding the 350 or drop the 455 in. Would that year 455 be worth it? I'm assuming those are pretty low compression low power motors? How easy would the swap be if i choose that? How much do you think it would cost to have the bottom end done on the 350? Trying to weigh my costs/choices here
You will want a different converter. The trishield one will probably flash to 3800-4000 on a 455 but trans and rear will be decent. A lot more torque down low. Mill heads and a clean up bowl port. Tune like you tuned 350. Should do well even stock.
Thanks Andre, If the 455 has good compression and ends up being a solid runner, if the head work helps it then i will have that done while its out, I assumed these years were dogs and dont want to end up unhappy once its in. Anything I can do to help it i will do. anything else helpfull that could be done? within reason that is lol.
A 455 will have more torque down low than the 350 will, but once you've run thru the torque range down low, a mid 70's ('75/'76) wheezer 455 will flatten out as far as horsepower when the rpm climbs unless you build it for higher rpm power.
What would be some good steps to take to get more of that RPM power? i dont mind having lots of head work done, or a cam, i just dont want to get into the bottom end if thats the case.
Probably want to find out year first. 75-76 heads are larger chamber. A set of 71-74 heads with some milling will kick up the compression. Maybe close to 8.8-9.0 depending on amount milled . Then look at the crower level 3 cam for 455, because ta is currently out of stock on 455 Ta 212 or 284-88 cams. then a 68-71 stock intake is worth a few ponies over the later emissions intakes. So you can easily add 50 plus. Hp and lots of lower torque. Having that torque and not revving past 4500 is good .
Thanks man, he thinks its a 74 but I'll try to get the confirmation on the exact year. im sure I can get buy an intake from him as well, hes a big Buick guy and has tons of parts. say it ends up being a 75-76 would the heads be considered boat anchors and id want to look for another set? or would it be better to just pass on it all and keep looking.
Unfortunately that’s where the 455 has issues, the bottom end, the HUGE mains need plenty of oil to survive at higher rpm, that plus the block is structurally weaker than the deep skirt 350
Well I do enjoy my small block and wouldnt mind having it completely redone at some point. i guess I could always just drop the 455 in and enjoy it as a cruiser for a couple years or so and get the 350 done in the meantime.
I think you will enjoy the 455 as much as the 350. You will miss the trishield converter. But , check on the heads first, if that’s the problem then easy to replace one head. As far as 75-76 oiling, a ta backgrooved front cam bearing and you should be good, and with a stock cam not revving past 4500, it should last
Can the converter be changed to work with the 455? are they compatible or are they completely different? i only have this TriShield one and the stock one. I think Im going to grab the engine either way, its apparently a real smooth runner, and weigh my options from there. thanks guys
Pretty sure JW can restall your convertor to work with the 455. Put a set of 70 -71 small valve heads on it with a 70 71 intake...Jim
