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#1 |
Registered User
Join Date: Sep 2020
Location: Kennewick, Wash.
Posts: 232
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307 Stroker Anyone???
I want to add some grunt to my lil 307. I know I'm gonna catch hell for wanting to keep the same engine instead of swapping to some other engine, but that's what's gonna happen.
I want to add a 3.75" stroke crank from Summit and the 400 SBC 5.565" rods. This will make it a 360 (359) cubic inch. The only problem is the available pistons will be .070 out of the hole. I can get thicker head gaskets or mill my pistons. Ready......GO!!! |
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#2 |
Senior Member
![]() Join Date: Oct 2012
Location: mountain view arkansas
Posts: 1,305
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Re: 307 Stroker Anyone???
I like different I say go for it
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#3 |
Post Whore
![]() Join Date: Feb 2016
Location: Portland Oregon
Posts: 11,141
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Re: 307 Stroker Anyone???
Do it. Worst case you might have to get some custom pistons made. Have you figured out the static compression ratio? This one from Diamond pistons is my favorite. I've built several Pontiac strokers over the years. Figuring out all the details is enjoyable for me.
https://diamondracing.net/p-10-compr...alculator.html
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. ![]() RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377 |
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#4 |
Senior Member
![]() Join Date: Dec 2009
Location: TN.
Posts: 8,109
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Re: 307 Stroker Anyone???
Sounds like Fun.
![]() The (self proclaimed) Engine Guru's are going to have something to say about this. ![]()
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________________________________________________________________________________________ ____________________________________________ 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build |
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#5 |
Senior Member
![]() Join Date: Jan 2001
Location: Orem, Utah
Posts: 7,912
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Re: 307 Stroker Anyone???
I'm just curious what the benefit will be.
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I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson |
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#6 |
Registered User
Join Date: Sep 2010
Location: Hancock Md
Posts: 405
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Re: 307 Stroker Anyone???
Nothing wrong with hot rodding a overlooked engine like that since its still SBC and parts availability is huge (other than the odd bore piston deal) more cu.in with small bore should pair well with mild cam for low end torque, only thing you would be giving up over a larger bore like a 350 would be airflow around valves but that is mainly higher rpm problem anyhow.
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#7 |
Registered User
Join Date: Sep 2020
Location: Kennewick, Wash.
Posts: 232
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Re: 307 Stroker Anyone???
I just talked with a tech guy at Silv-O-Lite pistons and he said my .030 over pistons are .482 thick at the top. That's PLENTY to take .070 off.
My next call was to the machine shop. They can mill all 8 for about $150. My buddy owns a shop and he had a set of 5.5656" 400 rods I picked up. The 307 (360) stroker is GONNA HAPPEN!!! |
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#8 |
Senior Member
![]() Join Date: Dec 2009
Location: TN.
Posts: 8,109
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Re: 307 Stroker Anyone???
Is a Dyno test in the plans (that's if you have a source close to you) ?
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________________________________________________________________________________________ ____________________________________________ 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build |
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#9 |
Registered User
Join Date: Sep 2020
Location: Kennewick, Wash.
Posts: 232
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Re: 307 Stroker Anyone???
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#10 |
Registered User
Join Date: Dec 2012
Location: Temple City
Posts: 3,591
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Re: 307 Stroker Anyone???
For pistons use Summit racing search engine.
If you know the bore you want to one that is feasible. You maybe able to get a piston with a different compression height to work that is commonly available. |
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#11 | |
Senior Member
![]() Join Date: Dec 2009
Location: TN.
Posts: 8,109
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Re: 307 Stroker Anyone???
Quote:
With that be Typed ![]() At the C10 Nationals at the Nashville Super Speedway in Lebanon,Tn ![]() They had a Mobile Dyno Trailer. ![]() It was Cool. ![]()
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________________________________________________________________________________________ ____________________________________________ 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build |
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#12 |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
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Re: 307 Stroker Anyone???
Any way you look at it you’re going to have serious money to upgrade the 307 with additional stroke. Unless you’re absolutely stuck on the numbers matching thing for the truck, 350 is just the way to go.
If you insist on the 307, I would skip changing the displacement and go straight for cylinder heads. The number one Achilles heel on your 307 is not displacement, it’s the outdated original cylinder heads. A cheap and easy that I have been doing for years: ‘96 and up 305 Vortec heads. They use a slightly different configuration chamber and A smaller intake valve than the same era 350 head. The smaller Intake valve will clear the smaller bore on the 307. They are not as common as the 350 head in the bone yards, but you still shouldn’t have too much difficulty coming up with a set. I have been been using these on 350 rebuilds for many years. The off idle response and low and torque is just incredible. Steve weim55Colorado |
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#13 |
Post Whore
![]() Join Date: Feb 2016
Location: Portland Oregon
Posts: 11,141
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Re: 307 Stroker Anyone???
Switching to Vortex heads would require either swapping to a Vortex manifold or modifying your existing manifold. Either way it's well worth it as the Vortex heads are that much better. They were the result of GM's development of the LT1 Corvette heads. Similar gains in efficiency, as the LT1 heads, over all the previous heads without the reverse cooling flow. You won't be disappointed with the power and MPG improvements.
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. ![]() RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377 |
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#14 | |
Senior Member
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Location: Near Canon City ,Colorado
Posts: 3,970
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Re: 307 Stroker Anyone???
Quote:
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'35 1/2 ton Pickup (bought 2020) '68 C10 Suburban (bought 2021) '72 K5 Blazer (bought 2013) '67 Stepside (bought 1997-sold 2021) '96 Bronco Eddie Bauer (inherited 2010) My 1st day here-'67 C10(sold)and '72 K5 Blazer http://67-72chevytrucks.com/vboard/s...d.php?t=702056 "Another Blue Chevy"(1935) http://67-72chevytrucks.com/vboard/s...d.php?t=799203 ![]() ![]() |
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#15 |
Post Whore
![]() Join Date: Feb 2016
Location: Portland Oregon
Posts: 11,141
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Re: 307 Stroker Anyone???
Here is an article with links on how to modify the intake if you want to go that way. There is a fair bit of interweb arguing about if it is a good way to go. The second article has lots of info on Vortex heads in general.
https://www.jalopyjournal.com/forum/...1-350.1073537/ https://nastyz28.com/threads/vortec-...e-guide.56505/
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. ![]() RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377 |
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#16 |
Senior Member
![]() ![]() Join Date: Mar 2016
Location: Near Canon City ,Colorado
Posts: 3,970
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Re: 307 Stroker Anyone???
Thanks
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'35 1/2 ton Pickup (bought 2020) '68 C10 Suburban (bought 2021) '72 K5 Blazer (bought 2013) '67 Stepside (bought 1997-sold 2021) '96 Bronco Eddie Bauer (inherited 2010) My 1st day here-'67 C10(sold)and '72 K5 Blazer http://67-72chevytrucks.com/vboard/s...d.php?t=702056 "Another Blue Chevy"(1935) http://67-72chevytrucks.com/vboard/s...d.php?t=799203 ![]() ![]() |
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#17 |
Post Whore
![]() Join Date: Aug 2013
Location: anamosa iowa
Posts: 54,517
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Re: 307 Stroker Anyone???
A pair of HO 305 heads will bolt right up. One other big ticket ($) would be a roller cam custom cut to your everything : displacement/compression/torque/trans/rear gear to get the absolute on the money results & freeing up friction & HP gained.
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#18 |
The Older Generation
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Location: Montezuma, Iowa
Posts: 25,492
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Re: 307 Stroker Anyone???
-
Here is my oddball. It's a 305 instead of a 307 but I have often wondered why someone would put that much time and money into this engine.... It came with a truck that I traded for. 305 Engine Specs 1989 1 piece seal block Balanced Roller Cam Hydraulic Roller Lifters 1.6 Roller Rockers .010, .010, and .030 Over Scat Rods Mahle light Weight Graphite Coated Pistons Low Drag Rings 1978-81 305 Heads, Fully Rebuilt 1.50” & 1.72” Valves Exhaust Ports Cleaned Up For Smoother Flow Edelbrock EPS powder coated intake Powder coated vintage style valve covers This engine was built for fuel efficiency 0 miles on engine I started it for the first time the other day. .
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
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#19 | |
Senior Member
![]() Join Date: Jul 2000
Location: North Texas
Posts: 3,490
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Re: 307 Stroker Anyone???
Quote:
Also, what did you plan for a cylinder bore? Hope you're not thinking about anything more than .060"over. In fact, if it cleans up at +.030", I'd stop right there. Finally, you must definitely get the rotating assembly balanced. As far as a somewhat unusual build, 20 years ago I built a 327 using a 350 4-bolt block, cast 307 crank, and K-B hypereutectic 327 pistons. I did get some flak for not building a 350, but I always liked the way 327s would rev. ![]()
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Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
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#20 |
Registered User
Join Date: Oct 2010
Location: Yakima Valley, Washington
Posts: 578
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Re: 307 Stroker Anyone???
A few years ago I built a ‘39 Ford pickup hotrod type rig. My uncle had a 307 under the bench that had been pulled from whatever it came in when it was fairly new. No history but people liked to talk down about 307s so it just sat, orphaned. I pulled the cam and found the lousy factory timing gear was so worn that the cam timing was retarded because of it. I put a mild 262 duration / .480 lift cam in, aluminum intake, HEI, and headers, otherwise stock. Sucker ran good and moved that little p/u nicely. Saginaw 4 speed and an 8” with 3.50 gears.
The main issue with a 307 is only its reputation. It was never used in a performance application, just as the basic, bottom option V8. Physically it is a 283 block with a 327 crank. In my 39 I called it just that- way more impressive to have a 283 stroker with 327 crank than a “boring” 307.. A mid sized cam, some better heads probably 1.94 valves, no need for 2.02s and the usual tricks and you’ll be having fun. If you do go with the full / long stroke crank and pistons, be sure to have a machinist confirm piston height and quench.
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1951 GMC 250 Open Express Pickup 1968 Suburban C10 1971 C20 Olive “People are shocked when they find out I’m not a good electrician” Dad told me “Son, never strike a man in anger- unless you’re certain you can get away with it” |
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#21 | |
Senior Member
![]() Join Date: Jul 2000
Location: North Texas
Posts: 3,490
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Re: 307 Stroker Anyone???
Quote:
Ah, but the lowly 307 was available only in one flavor--200hp with a 2bbl carb. Never mind it was a stroked 283, which was considered to be cool prior to the 327 introduction. When I bought my 69 C10 back in 89, it had the original 307 complete with noisy lifters and sluggish performance. Frist thing I did was replace the cam, lifters, and the worn-tooth timing set. I used stock parts purchased from an engine rebuilding company in Ft. Worth. The cam was probably the old 195/202 piece that was used in 283, 327, and even 350 engines over the years. Those parts and 2-inch dual exhaust with generic turbo mufflers made a big difference. Later I bought a used Q-jet manifold (interestingly from a 69 327), along with a Holley Economaster 450cfm Q-jet replacement carb. Man, that little 4-bbl made even a bigger difference, and completely transformed the truck. It was probably faster than the lighter 220hp/283-4bbl cars I had owned over the years. I can only imagine what it would have done with a small performance cam and bigger valves, even with otherwise stock heads. I eventually went to a 350 and even a 383 for awhile, but sometimes wish I would have just rebuilt the 307 short block and did something about the heads.
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Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then! |
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