250 to 350 conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

NicoSlam · 12-06-2010, 09:56 AM

I just wanted to show the progress I am making in switching my 69SWB from a 250 to a 350. The 250 was original and ran great other then a small flat spot on the monojet between idle and acceleration. I got a good deal on a stock 350 which I have done the following: complete rebuild plus flat top pistons, edelbrock 2102 cam, vortec heads, BS serpenting pullys, SS Headers, Carter AFB 625cfm and all new external components. Also going with an aluminum radiator and dual electric fan setup.

fattyarbuckle · 12-06-2010, 10:27 AM

sweet looking engine there!

Rich916 · 12-06-2010, 12:19 PM

No! Another 250 bites the dust...Ill take that power steering set up.

Jacfourteen · 12-06-2010, 12:45 PM

Both are great looking engines! let us know as you get closer, I can't wait for a video of that beast running.

RCbowtie69 · 12-06-2010, 07:24 PM

I love the pulley set up, who makes it, that the set up i need on my motor, what did they cost u, nice set up, looking good, keep on truckin'',

NicoSlam · 12-06-2010, 07:26 PM

billet specialties produces this as a kit. set you back about $500 but it looks great and everything aligns perfectly.

72BlckButy · 12-06-2010, 08:13 PM

Nice looking update...

swamp rat · 12-06-2010, 11:45 PM

Quote:

Originally Posted by NicoSlam

billet specialties produces this as a kit. set you back about $500 but it looks great and everything aligns perfectly.

Got a part number for the kit?

NicoSlam · 12-07-2010, 12:19 PM

Here is the part number directly from billetspecialties: FM2122PC

Ronnny · 12-07-2010, 05:52 PM

Nice swap you have thier. Both the motor out and in looks clean. Myself if i could swap my 68 lwb 350/400 for a straight 6 w/3 on the tree in a minute.

swamp rat · 12-07-2010, 10:57 PM

Quote:

Originally Posted by NicoSlam

Here is the part number directly from billetspecialties: FM2122PC

Thanks for the information!! It will definantly be put on my "do" list..

NicoSlam · 01-03-2011, 02:43 PM

Update: Well it has not gone as smoothly as expected. First off, using the L6 motor mounts, the headers were hitting the clutch linkage. I got a set of v8 mounts which moved the motor forward but now the clutch linkage doesn't align along with the manual crossmember. This was a good enough excuse to justify the cost of a 700R4 conversion. I removed al the manual stuff, changed steering column, and pedal assembly. Added brake booster which required the addition of a neutral safety wiring. I'm waiting for the TV cable and lockup to arrive from bowtie. Once I get the tranny prepped, I should attempt to install next weekend. Then I can get the drive shaft sized and then trailered to the muffler shop.

VDOG · 01-03-2011, 02:53 PM

Quote:

Originally Posted by NicoSlam

Update: Well it has not gone as smoothly as expected.

Hang in there, it sounds like you have the right plan. Im curious about the Edelbrock Cam you installed. I bought the same one and installed it in my 283but as I installed the heads, I broke a stud for the roller rockers. Got frustrated, and picked up a 92 LT1 for little of nothing. Anyway, so I never got to use the Edel Cam, and I cant use it in my 92 cause its roller cam.

So once its installed, I want to know how you like the power from the cam, is it a smooth idle, comes in at the right RMP, etc etc. Thanks.

NicoSlam · 01-03-2011, 03:00 PM

Vdog,

I will keep you posted. Its hard seeing the motor on a stand and not being able to run it. I still have not broken in the motor so I'll make sure to take video of the startup and idle. I know words dont come close to pics but there is nothing worth seeing yet. I'll get pics of my tranny teardown when I ge tthe parts in.

VDOG · 01-03-2011, 03:09 PM

Thanks Nico. I also have a 700R4 that came with the LT1, you mention the driveshaft. Is that something im going to have to address, (driveshaft) when I install mine? First of me hearing this.

Thanks.

NicoSlam · 01-03-2011, 03:20 PM

Well I haven't installed the engine/tranny yet but this is what I have gathered. My original setup was an L6/3-speed, therefore the motor was set further away from the radiator. The v8 motor mounts pushed the motor about three inches closer to the radiator. Now from what I gather, a 700R with v8 motor mounts would require one to shorten the DS by 3" but my DS is from a L6 setup so I I think that moving the motor forward and using a L6 DS, I may not need to shorten the DS but I have to wait and see. I may do some measurements tonight and let you know. Being your going with an LT1, it may be different for you. I guess this is the stuff that makes this hobby fun.

VDOG · 01-03-2011, 03:32 PM

Sometimes its fun, other times its hell. LOL
My LT1 is in now and runs great, just need a bit more umph.

Heres the link to the install.

http://67-72chevytrucks.com/vboard/s...highlight=vdog

vasquezmrysvll · 01-03-2011, 04:23 PM

may want to look into running mismatch heads.... looks to be one 062 vortec and one 906 vortec?

Hubscrub · 01-03-2011, 08:13 PM

i did the inline 6 to 350 bored 0.60, 700r4 swap a couple years ago..... thinking i miss my 6 with 3speed

swamp rat · 01-03-2011, 08:20 PM

Quote:

Originally Posted by vasquezmrysvll

may want to look into running mismatch heads.... looks to be one 062 vortec and one 906 vortec?

Wow nice catch!!

brans72 · 01-03-2011, 08:23 PM

I put a 350 in our 67 with 700r4 trans and moved stnds foward (which I got some V8 stands) and driver shaft seeems to fit perfect but yet to start truck.

NicoSlam · 01-04-2011, 10:42 AM

The heads are both 062 (three humps). the single half moon you see on the d-side head is just whats on the opposite end of a 062 head . The 906 has a single hump thats similar.

vasquezmrysvll · 01-04-2011, 01:14 PM

i have the "saw tooth" on both sides of my heads. only way iv ever seen them? also the heads are non-directional.

NicoSlam · 01-04-2011, 02:58 PM

Quote:

i have the "saw tooth" on both sides of my heads. only way iv ever seen them? also the heads are non-directional

I'm not disagreeing with your comment but apparently something alse is going on which may not have anything to do with the heads being 906 or 062. Apparently mine do not have saw tooth marks on both sides of the heads as your do and no literature I have read makes that statement. Maybe I have repos that have both the marks of a saw tooth (062) and the hump of a (906). When I get home, I'll check the casting numbers. That should tell me what I have regardless of shapes etc. I'll post pics this afternoon. Hopefully someone else can chime in.

vasquezmrysvll · 01-04-2011, 03:10 PM

just saying, the saw tooth is more desirable, if your builder advertised "vortecs" you should AT-LEAST get a matching pair, that flow the same numbers. goodluck

12-06-2010, 09:56 AM	#1
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	250 to 350 conversion I just wanted to show the progress I am making in switching my 69SWB from a 250 to a 350. The 250 was original and ran great other then a small flat spot on the monojet between idle and acceleration. I got a good deal on a stock 350 which I have done the following: complete rebuild plus flat top pistons, edelbrock 2102 cam, vortec heads, BS serpenting pullys, SS Headers, Carter AFB 625cfm and all new external components. Also going with an aluminum radiator and dual electric fan setup. Attached Images

12-06-2010, 10:27 AM	#2
fattyarbuckle Registered User Join Date: Nov 2010 Location: St. Louis Mo. Posts: 282	Re: 250 to 350 conversion sweet looking engine there!

12-06-2010, 12:19 PM	#3
Rich916 Registered User Join Date: Dec 2009 Location: Rancho Cordova, CA Posts: 274	Re: 250 to 350 conversion No! Another 250 bites the dust...Ill take that power steering set up. __________________ 71 Short Step Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=429946

12-06-2010, 12:45 PM	#4
Jacfourteen Big Red - Now its a SWB! Join Date: Jun 2009 Location: Oroville, Ca Posts: 1,624	Re: 250 to 350 conversion Both are great looking engines! let us know as you get closer, I can't wait for a video of that beast running. __________________ 68 3/4 ton (Project)-350 Small Block, .030 over, 10:1 comp, 3998993 heads, C3BX edelbrock intake, comp cams XE268, Holley 670 SA, long tube headers, dual flow 40's, E-fan, Alum rad, currently under the knife getting shortened and bagged build thread 41 3/4 ton (wife's)-flatbed, fully restored to original 01 Tahoe LT 4WD (my daily driver)-Magnaflow Muffler, Rollin on 22's 02 Ford Mustang Convertable (Wife's Car)-Flowmaster 50, Clear corners, Intake, sittin on 18's

12-06-2010, 07:24 PM	#5
RCbowtie69 Registered User Join Date: Dec 2003 Location: Thomasville, NC Posts: 1,877	Re: 250 to 350 conversion I love the pulley set up, who makes it, that the set up i need on my motor, what did they cost u, nice set up, looking good, keep on truckin'',

12-06-2010, 07:26 PM	#6
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	Re: 250 to 350 conversion billet specialties produces this as a kit. set you back about $500 but it looks great and everything aligns perfectly.

12-06-2010, 08:13 PM	#7
72BlckButy Tot Roddin' Join Date: Apr 2005 Location: Mid-MO Posts: 24,461	Re: 250 to 350 conversion Nice looking update... __________________ -Nate 1969 CST SWB - Project Blank Slate (4.5/6" ECE Static Drop, 6-lug disc brake upgrade (manual), Billet Specialties Vintec 20x8.5 255/40 (F) 20x10 295/40 (R), 250 I-6) 1960 AMF Skylark - Tot Roddin' (Lowered with custom frame; soon to include custom push bar and interior) 2008 Silverado CrewCab 1LT (5.3L, 3:73, 4x4, LT1, Z-71, Towing Package)

12-07-2010, 12:19 PM	#9
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	Re: 250 to 350 conversion Here is the part number directly from billetspecialties: FM2122PC

12-07-2010, 05:52 PM	#10
Ronnny Registered User Join Date: Aug 2010 Location: newnan Posts: 60	Re: 250 to 350 conversion Nice swap you have thier. Both the motor out and in looks clean. Myself if i could swap my 68 lwb 350/400 for a straight 6 w/3 on the tree in a minute.

01-03-2011, 02:43 PM	#12
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	Re: 250 to 350 conversion Update: Well it has not gone as smoothly as expected. First off, using the L6 motor mounts, the headers were hitting the clutch linkage. I got a set of v8 mounts which moved the motor forward but now the clutch linkage doesn't align along with the manual crossmember. This was a good enough excuse to justify the cost of a 700R4 conversion. I removed al the manual stuff, changed steering column, and pedal assembly. Added brake booster which required the addition of a neutral safety wiring. I'm waiting for the TV cable and lockup to arrive from bowtie. Once I get the tranny prepped, I should attempt to install next weekend. Then I can get the drive shaft sized and then trailered to the muffler shop.

01-03-2011, 03:00 PM	#14
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	Re: 250 to 350 conversion Vdog, I will keep you posted. Its hard seeing the motor on a stand and not being able to run it. I still have not broken in the motor so I'll make sure to take video of the startup and idle. I know words dont come close to pics but there is nothing worth seeing yet. I'll get pics of my tranny teardown when I ge tthe parts in.

01-03-2011, 03:09 PM	#15
VDOG Grand PooBaa Member Join Date: Jan 2001 Location: LA, CA Posts: 5,302	Re: 250 to 350 conversion Thanks Nico. I also have a 700R4 that came with the LT1, you mention the driveshaft. Is that something im going to have to address, (driveshaft) when I install mine? First of me hearing this. Thanks.

01-03-2011, 03:20 PM	#16
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	Re: 250 to 350 conversion Well I haven't installed the engine/tranny yet but this is what I have gathered. My original setup was an L6/3-speed, therefore the motor was set further away from the radiator. The v8 motor mounts pushed the motor about three inches closer to the radiator. Now from what I gather, a 700R with v8 motor mounts would require one to shorten the DS by 3" but my DS is from a L6 setup so I I think that moving the motor forward and using a L6 DS, I may not need to shorten the DS but I have to wait and see. I may do some measurements tonight and let you know. Being your going with an LT1, it may be different for you. I guess this is the stuff that makes this hobby fun.

01-03-2011, 03:32 PM	#17
VDOG Grand PooBaa Member Join Date: Jan 2001 Location: LA, CA Posts: 5,302	Re: 250 to 350 conversion Sometimes its fun, other times its hell. LOL My LT1 is in now and runs great, just need a bit more umph. Heres the link to the install. http://67-72chevytrucks.com/vboard/s...highlight=vdog

01-03-2011, 04:23 PM	#18
vasquezmrysvll "the other guy" Join Date: Oct 2008 Location: Olivehurst California 95961 Posts: 901	Re: 250 to 350 conversion may want to look into running mismatch heads.... looks to be one 062 vortec and one 906 vortec? __________________ God Said,"Building A 10 Second Import Is Like Coming Out Of The Closet, In The End Ur Still....."EXPLETIVE"



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01-03-2011, 08:13 PM	#19
Hubscrub Cruzin Join Date: Dec 2009 Location: on the road Posts: 2,835	Re: 250 to 350 conversion i did the inline 6 to 350 bored 0.60, 700r4 swap a couple years ago..... thinking i miss my 6 with 3speed __________________ Lime Wife's 67https://www.google.com/url?sa=t&rct=...wZEMODaS2d94u8 Back to the Fifties 59 https://www.google.com/url?sa=t&rct=...NAeStpydfrcj_U Proverbs 3:5,6 "Thanks to the Interstate Highway System, it is now possible to travel across the country from coast to coast without seeing anything."Charles Kuralt In memory of our first baby daughter, daddy and mommy love you. Danica Grace 6/26/14

01-03-2011, 08:23 PM	#21
brans72 Registered User Join Date: Dec 2009 Location: Durham,NC Posts: 636	Re: 250 to 350 conversion I put a 350 in our 67 with 700r4 trans and moved stnds foward (which I got some V8 stands) and driver shaft seeems to fit perfect but yet to start truck.

01-04-2011, 10:42 AM	#22
NicoSlam Registered User Join Date: Nov 2009 Location: San Antonio TX Posts: 251	Re: 250 to 350 conversion The heads are both 062 (three humps). the single half moon you see on the d-side head is just whats on the opposite end of a 062 head . The 906 has a single hump thats similar.

01-04-2011, 01:14 PM	#23
vasquezmrysvll "the other guy" Join Date: Oct 2008 Location: Olivehurst California 95961 Posts: 901	Re: 250 to 350 conversion i have the "saw tooth" on both sides of my heads. only way iv ever seen them? also the heads are non-directional. __________________ God Said,"Building A 10 Second Import Is Like Coming Out Of The Closet, In The End Ur Still....."EXPLETIVE" Last edited by vasquezmrysvll; 01-04-2011 at 01:16 PM.

01-04-2011, 03:10 PM	#25
vasquezmrysvll "the other guy" Join Date: Oct 2008 Location: Olivehurst California 95961 Posts: 901	Re: 250 to 350 conversion just saying, the saw tooth is more desirable, if your builder advertised "vortecs" you should AT-LEAST get a matching pair, that flow the same numbers. goodluck __________________ God Said,"Building A 10 Second Import Is Like Coming Out Of The Closet, In The End Ur Still....."EXPLETIVE" Last edited by vasquezmrysvll; 01-04-2011 at 03:10 PM.

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