Swap 250 engine and saginaw 3sp to 350 engine with t-350 or another manual?
Big question. Or suggestion. I have a 79 c10 with a sixpack and three on tree. I recently acquired a 74 model .350 engine with a th 350 bolted to it. I just wanted some input on either going to the th 350 or finding another manual transmission pros and cons of both and your personal prefs. Thanks for all input.
02-02-2011 09:43 PM
6 to 8
Done a few with t350, the 6 cyl sits back further than an 8cyl, so the 8 will bolt right in but sits back close to the firewall, especially the distrib. If you don't mind this you can usually use the same drive shaft for length. Sometime you have to swap yoke length only. If you want to keep the same 2 core rad just add an electric fan for better cooling. :thumbup:
02-03-2011 02:15 AM
Bellhousing to block interface is at the same point in the chassis and relative to the firewall, the V8 does not sit farther back than the staight six, so the same trans crossmenber is used with both transmissions, on either engine. From the back of the block to the transmission mount is the same distance on both the 3-speed manual and the TH-350 automatic.
The entire clutch/flywheel/bellhousing/transmission from the 250 will bolt right to the 350 V8, flywheel balance is the same, if you want to stay manual transmission.
You will need V8 block mounts for the truck to install the 350. Small block V8 bracketry for the power steering pump if you have power steering.
02-03-2011 03:56 AM
Thanks. If I used the th350. Would a new floor shifter be sufficient or would I have to get a new steering column?
02-03-2011 04:19 AM
You can use a floor shifter just fine.
02-03-2011 04:53 AM
Thanks man any suggestion on heads and cam? Id like to go through engine before I put it in and this is my first build.
02-03-2011 06:54 AM
Should someone point out that a 74 era 350 probably doesnt make any more power than the stovebolt 6? Personally I love seeing trucks with inline 6's at car shows...cuz there arent any. Heads and cam? Eh hell Modified vortec style heads and a 268H? Go with a small cap HEI or pertronix ignitor 2 or 3 conversion. Par for the course PM AirGap style intake as well... It will be lost in a sea of like trucks. Enjoy it in good health; take a good look at your front suspension when you yank the motor. I have no idea if there are any suspension differences between the stovebolt and the V8.
a 250hp inliner with a split manifold would be cool...put a T5 behind it
02-03-2011 07:28 AM
Yes I love the inline but it has 100000 on it now. It should last a while but when it goes I want to be prepared. I still drive it almost daily and mpg is great!
02-03-2011 07:36 AM
Im partial to custom Muncie 4spds. 2.98 1st gear and 3.23s in the rear
02-03-2011 08:39 AM
And yes it has almost the power of a 350 and it actually pulls trailers better than my k5 due to the manual tranny. Fact is a rebuilt 6 costs about 400 more than a 350. So I bought a hopped up 350 that came with headers cherry bombs a radiator and a th 350 for 450 bucks. Couldn't pass on it.
02-03-2011 09:51 AM
Cant beat that. Define 'hopped up.' Maybe just leave it and build a stickshift? What heads cam and intake does it have?
02-03-2011 10:01 AM
Unsure what hopped up meant. I haven't went through it yet. I figured I couldn't get a block or a th350 core let alone all the other things for 450.00 bucks. And get this, I forgot my ratchet straps so he tied it down with no 1 copper wire. Lol
02-03-2011 03:40 PM
6 to 8 cyl
In my factory 1967 to 1976 General motors service manual it actually shows the frame is drilled ahead of 6 cyl mount to move crossmember ahead for 8 cyl install and preceeds to mention the trans crossmember is also drilled for same reason also mentions diff yoke length of 2.5 inchs. I have installed both ways as stated and with 6 cyl placement. Just saying what Gm states. Both work, but large distrib cap rubs cab.
02-04-2011 10:17 PM
Found a floor shift today...actually found a pot ofgold. This man has been stockpiling old gm truck axles and parts for years and due to economy is letting alot go cheap.hope to finish liift kit on blazer and get it ready for paint this week. Will post pics on the build of the 79. Blazer almost finished so ill post finished pics of it. Thanks for all the help