Oldsmobile 374 stroker build

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
I have decided to work within my budget and not go with the 403 build. It will be an iron head, roller cam, Olds 350 with a 4.125" bore and 3.5" stroke and a 2004R and 3.90 posi for my 70S. I already contacted Parkland Engine Builder's for machine shop price. I plan to have it stripped out by Christmas Eve and hopefully drop it off, there will be a wait. It will come at a great cost but there will be some benefit for all you guys, you will see.
My current parts run down
completely untouched 76 short block
330 forged steel crank offset ground to 3.5" stroke by Ohio crank.
Scat sbc 6" long, 2" journal rods and rod bearings
Clevite cam bearings
ARP 7/16" head bolts
ARP 1" longer 302 main studs for a Halo or girdle. FYI 302 main are the same length as 1-4 SBO mains.
1/2" CNC Halo, better made than the J+S Halo
Hydraulic Roller lifters
I also have Performer and RPM intake. I also have a 1" open aluminum spacer, modified for less air restriction. I may try the spacer on the RPM intake.
Fully rebuilt with a couple of thousand miles #6 iron heads 2.07/1.56 valves,with positive seals machined and the bowls opened with a bowl hog cutter. I am pocket porting them over the next couple of weeks, may do a separate thread.
Comp Cams 1.6 roller tip and Scorpion 1.72 full roller rocker arms, both for 3/8" studs, guide plates and 5/16" to 3/8" conversion studs.
Everyday Performance custom 800 cfm Qjet with adjustable APT
Mallory Breakerless distributor, adjustable mechanical and vacuum advance, set to 18 mechanical in by 2800 and 11 degrees of vacuum advance.
Mallory Hyfire 6AL with adjustable rev limiter, will set to 6000.
Serpentine belt drive and new Flowkooler Billet impeller, reverse rotation water pump on the way
New A body replacement aluminum/plastic rad
Dodge Stratus Fans
Good TH2004R trans, 86 model appears rebuilt, shifts perfect, needs upgrades.
PATC 2200 to 2500 stall, flashes at 2350 stall and deep trans pan with drain plug and a stacked 5000 rpm governor modified by me.
Sanderson shorty headers with custom 2.5" X pipe dual exhaust with shitty 2.5" tail pipes. Terrible job with a terrible price. I should have bought Flowmaster tail pipes and installed the tail pipes myself. Hack jobs like this is why I do all the work on my own cars, all 5 of them. I will add an O2 bung for a wideband tuner.
Remember these are the parts I HAVE, not what I want or need.
 

Olds 307 and 403

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Oct 4, 2018
729
226
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Melville, Saskatchewan
Ready to pull
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Going to start pulling valves soon.
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Olds 307 and 403

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Thread starter
Oct 4, 2018
729
226
43
Melville, Saskatchewan
I found a Mahle 2618 forged 4.065" bore, 7.9cc dish, 1.550" compression height, 1mm/1mm/2mm ring pack piston. That equals 363 CI, interesting. The Icon piston is also 2618, older 1.5mm ring pack and 15.2cc dish, needs 62cc chambers for 9.6 to 1 with 0 deck, even with the larger bore. I would not mind polishing the combustion chamber, nice and smooth. According to the compresion height calculator, with the 3.5" stroke and 9.33" deck height, a 1.58" compression height is needed. Either piston is .019" to .030" in the hole. If this is right, I would deck it .020" and use a .030" MLS head gasket. Not looking for a max ci build, using the huge pile of parts I have for a reliable, cool running street and maybe a once or twice a year strip build. The bores look really good, hone to fit should save some $$$, will see what Parkland Engine Rebuilders say.
 

Olds 307 and 403

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Oct 4, 2018
729
226
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Melville, Saskatchewan
Motor out, all pulled apart. All the rod bearings were scored, surprisingly the bent rod bearing was no worse. The cam had multiple lobes with wear compared to others, failing on multiple lobes. Not bad for a 45+ year old short block, $120 for the complete 76 350 with great oil pressure and comp, ran for probably 5 years. Fully rebuilt #6 heads with 2.07/1.56 valves with a bowl hog cut, $400 cost, was $1200 worth of machine work and parts supposedly. It was $225 US for the cam and lifters. I used the garbage Cloyes Street roller timing set, they were slack new, not going that way again. A pile of snow Tuesday so I will take the block Christmas Eve, if they are open and the call goes well tomorrow.
 

Olds 307 and 403

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Oct 4, 2018
729
226
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Melville, Saskatchewan
Well all the bearings were toast, just the rod bearings were worse. Intake valves are 2.07 confirmed by the caliper. They are close to the edge of the chamber. There must be a burr on the edge of the exhaust valve, could not pull the valve out, moves fine till the very edge
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Olds 307 and 403

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Thread starter
Oct 4, 2018
729
226
43
Melville, Saskatchewan
Talked to Parkland, talked to Dean I believe. They are open till Wednesday and then closed to January 4th. At least a couple weeks till they can touch it. I will try and kiss the wife nice for her to drop it off or I will take Wednesday off. The wrench in it all, there is supposed to be 40 cm of snow tomorrow. Our family is famous for going out in the worst conditions possible. I guess the 4x great Uncle, Dr John Rae, the Arctic explorer, is a part of us.
 

Olds 307 and 403

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Oct 4, 2018
729
226
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Melville, Saskatchewan
I did a quick clean up of the oil pan and put it back on the motor, so it won't be sitting on the mains during transport. The SB pan clears the Halo, which is good, the BBO replacement pan should allow a little more room. I will lay down a tarp, put the motor in the back on a tarp and another tarp over top weighed down. I will fog the motor with storage spray. I am hoping my Wife can drop it off tomorrow but it will depend on road conditions.
 

Olds 307 and 403

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Thread starter
Oct 4, 2018
729
226
43
Melville, Saskatchewan
Block at the machine shop, it may take a month, they are busy.
 
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Olds 307 and 403

Active member
Thread starter
Oct 4, 2018
729
226
43
Melville, Saskatchewan
These parts arrived today. I am installing the fan controller this weekend. I am leaving the rad for the new motor. Speaking of that, still no word from the machine shop, hopefully soon so I can order pistons. FYI, I have $1000 just for the starter, rad and fan controller. The strokes and ground undersized 330 crank, 1/2" Halo and studs, another grand.
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