NOS Chevy "factory high performance" 307 engine?

[lowmile]

Anyone familiar with these engines I purchased two early 70's NOS 307's from an old boat dealership along with two NOS 1967 Buick 300 engines. They have deep groove pulleys, LT1 valve cover's, 4 barrel intakes, and also have windage trays. I've found a little info on the web but not much. Any help would be appreciated. Thanks mark

[67 Nova Boy]

Super Stock engines?

Dave
67 Nova Boy

[lowmile]

I found this on the web.

"Chevrolet 307 V8 Engine


The Chevy 307 V8 engine came along in 1968 to replace the Chevy 283 V8. The engine was used in lower performance oriented family type cars and was equipped with a 2 barrel carburetor. After 1973 the 307 was chopped from the GM line engine lineup.
One interesting fact regarding the Chevy 307 V8 was that it was also manufactured by GM for boat use and sold by the Outboard Marine Corporation as a high performance marine engine. The marine version of this engine produced between 235 and 245 horsepower and even used the same aluminum valve covers that were used in Corvettes and Camaro Z-28s."

[earntaz]

Hmmm -- good info ... I know they pulled pretty good for a small CI motor.

[Lynn]

Had no idea. What's the number on the carb?
Guessing the intake is same as a 350 of the same vintage?

[marxjunk]

There a guy local that owns a boat salvage and I go there when I can and look at stuff often..he has some HP 307s and a few HP 318 Chrysler motors he has pulled out of old 70s boats...he's had some for a decade and no one wants them....as neat as they sound very limited market..and with the revolution of crate motors in the past 2 decades doubt if he will ever sell them

I buy all the 327s 350s and 400 small blocks and all the big block Oldsmobile stuff he comes up with..and really score some cool rare stuff....like a dual quad nail head motor once..it was in an early fiberglass boat with tail fins.

[WILMASBOYL78]

It would be interesting to know if there was a different cam or other special components. I always liked the 307...they ran forever...made decent power...simple to work on.

wilma

[PeteLeathersac]

Any pass' front extended deck/pad stampings?
<<GRAEMLIN_URL>>/hmmm.gif
~ Pete

[mssl72]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PeteLeathersac</div><div class="ubbcode-body">
Any pass' front extended deck/pad stampings?
<<GRAEMLIN_URL>>/hmmm.gif
~ Pete</div></div>

Exactly what I was gonna ask Pete!

[lowmile]

I'll get the pad stamps tomorrow. A few years back I purchased two NOS LS7's out of the same boat dealership. All of these engines have been in the same spot for the last forty years. I remember seeing them when I was in high school. He's about ready to pack it in. I also purchased a complete (down to the date coded plug wires) 427. It came out of a station wagon that was wrecked with less than 10k miles on it. He used it to pull boats!

[njsteve]

Are the marine engines reverse rotation?

[lowmile]

They are standard rotation, He's had them a while but he doesn't forget ANYTHING! They also come with vintage Mallory distributors, something about the GM version had an open spark which is a no no on a boat.

[bbbentley]

Very interesting, never knew about the marine 307. I don't have anything against any small block Chev. , but that was one engine that was ok for transportation and never considered by myself or buddies to &quot;hop up&quot;. The small bore, long stroke just did not make sense to race. Too restrictive breathing as the valves too close to cylinder walls, IMO. I wish I had one 307 now, that I passed on, BITD. It is the one out of the yellow 69 Camaro I have. The eng. code is DE if y'all ever come across one. I am willing to bet not too many were put in front of a 4 spd. like this one ? When I bought the car, I had been married for 3 years and while we were making our bills, we did not have a lot of extra cash. I had parted out a couple of cars earning the wife's approval to bring home cars I deemed to part out. The guy had the engine, 307, but he had it boiled out and bored .040. I thought, were would I find slugs for that? and why would I invest in such an engine? So, I bought the car and passed on the engine. Guy wanted $200 for each (car or 307). I ended up keeping the car, why, I don't know? My neighbor who was the same age and we pal'd around bought a nice 68 Nova 307. He was afraid to drive it because of the racket it made. Finally, wanting to help him, I had him open the hood and put it in gear and stand on the brake while giving it some gas. Found the problem. A broken L motor mount. That thing was ready to jump out of the engine bay, lol. Other than a couple of 72 307 pick ups, that is all my 307 experiences (Not true, had a couple of 70 Camaros with 307s but another time perhaps). Just thought guys would like a peak into the window of my life, so I share. Hope I did not Hi-jack or get too off topic?

[lowmile]

BBBenny If a topic on a 307 high performance engine couldn't wonder off in a different direction, I don't know what would. LOL

[volquartsen]

I have a 1970 Slickcraft boat that has a chevy 307, motor is marked as a OMC...
Wondering if this motor would be the same as the high performance motor?

[bracketracer-78]

Back in 1988 my dad and I pulled the original 307 out of my 1972 Chevelle to swap in a 350. My dad had no idea what to do with the 307 so he bairied it in the backyard. It's still there. If anyone wants it bring a shovel.

[bbbentley]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lowmile</div><div class="ubbcode-body">BBBenny If a topic on a 307 high performance engine couldn't wonder off in a different direction, I don't know what would. LOL </div></div>

No disrespect to my brother from another, bbbenny, I am bbbENTLEY, but ok, nonetheless, appreciate the compliment,lol.
Appreciate the humor in &quot;letting me down easy&quot; on the different direction, but as a Cincinnati,Oh. Hillbilly, &quot;marine&quot; was where your cousin went to serve our country, not talked in engine circles around these parts,lol.

[Tommy]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WILMASBOYL78</div><div class="ubbcode-body">It would be interesting to know if there was a different cam or other special components. I always liked the 307...they ran forever...made decent power...simple to work on.

wilma </div></div>

Great motors. 200 hp and real smooth. They feel strong with a taller gear out back. I bought a 68 Nova with a 307,Glide and 3:08. swapped in a 3:73 and a M21 and the little mouse was a lot of fun. later I sold the engine to a guy and he dropped it in a 65 C10. He says it runs fine and pulls strong in front of his 3 on the tree and 4:10s.

Tommy

[Verne_Frantz]

By July '69, Tonawanda shipped 4976 307s for a 4-spd under two different part numbers. There were also 2 COPO 307s shipped, one for the M35 and 10 for the M38.

Verne <<GRAEMLIN_URL>>/flag.gif

[lowmile]

Yes these came out of an OMC dealer. The pad stamp is VO7114CX

[budnate]

Lets see the 427 ........ <<GRAEMLIN_URL>>/biggthumpup.gif

[lowmile]

Sorry it was a few years back on the 427 about the time I purchased the LS7's. They were before I had a cell phone with a camera. lol I do have a pic of where one of those wound up.

[lowmile]

I know where Chevy found the extra 45 HP in these 307's An nice set of 186 heads. The engine casting dates are June and July of 1970.

[PxTx]

The casting marks on the end did't look like 186 markers. I guess these are 1.94 valves too since a 2.02 needs a bigger bore. It is an interesting combination!

[novadude]

Those look like <span style="font-weight: bold">185</span> heads, which would be correct for a '69 200hp 307. 69cc chambers, 1.72/1.50 valves. Not a performance head. I'm guessing the extra hp was from the Q-jet and intake + *maybe* a cam??

[Fast67VelleN2O]

Interesting that this motor is equipped with the blue paint push rods. That's some factory HP stuff right there.