swapping 250 for the 350; frame mounts - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70heavyhalf · 08-18-2007, 11:17 PM

Hey guys, I am going to swap my 250 6 cl for a 350 and I was wondering if the frame mounts(for the motor) would work or do I need to buy new ones, and if so, who carries them.
thanks in advance

roadking · 08-19-2007, 09:09 AM

You will need the v8 towers (frame mounts). also you'll also need to move the engine foward to the foward mount holes on the frame. This will put your engine in the correct v8 position, this looks better and gives you a extra inch between the firewall and distrbuter otherwise it will not allow you much clearence. do a search, this topic has been covered many times.

71Rat · 08-19-2007, 08:07 PM

the PO of my truck put a v-8 in the I-6 position, yeah it looks set back far but it doesnt have any problems

Brock · 08-19-2007, 11:59 PM

I'm gonna be doing the same thing except from a I-6 292 (doesn't run) to a 307. Are these the "towers" your refering to?

http://cgi.ebay.com/ebaymotors/ws/eB...154172891&rd=1

I've read on here that you also need to move the mounts 3" forward to allow room for the distributer not to be cramped, is this right?

I've got a brother-in-law that'll actually gonna do the swap (I'll be assisting) I just want to make sure we have all of the right parts and tricks.

glock35ipsc · 08-20-2007, 12:08 AM

You CAN run a V-8 in the I-6 position without any problems. My 68 was like this for years until I started the rebuild. I even ran an HEI, installed with no problems. I am moving it into the V-8 position just because I can.

*Shane* · 08-20-2007, 12:29 AM

glock is right ... you can run a small block on the I6 towers ... my '67 was that way when i got it and it ran fine.

Brock · 08-20-2007, 01:22 AM

Is there any mod needed down the line (drive shaft, rearend)?

I'm going with a 700r4 from a 3-OTT

mexgrhd68 · 08-20-2007, 06:34 PM

Quote:

Originally Posted by Shane

glock is right ... you can run a small block on the I6 towers ... my '67 was that way when i got it and it ran fine.

2bits · 08-20-2007, 06:42 PM

If you do the factory set up and move the engine forward, yes you will have all the stuff that goes along with it. Tranny lines will be too long, driveshaft will be too short, need to move the tranny crossmember, and the shifter linkage too. All the frame holes were pre-drilled from the factory on mine, so it was just a matter of moving everything and having the driveshaft re-done. I got some generic brake line from Oreillys for cheap and hand formed them as tranny lines.

08-18-2007, 11:17 PM	#1
70heavyhalf Registered User Join Date: Jul 2006 Location: CA Posts: 69	swapping 250 for the 350; frame mounts Hey guys, I am going to swap my 250 6 cl for a 350 and I was wondering if the frame mounts(for the motor) would work or do I need to buy new ones, and if so, who carries them. thanks in advance __________________ 70' 1/2 ton 2wd 350/muncie m-20/12-bolt rearend Darin

08-19-2007, 09:09 AM	#2
roadking Registered User Join Date: Nov 2003 Location: kc Posts: 229	Re: swapping 250 for the 350; frame mounts You will need the v8 towers (frame mounts). also you'll also need to move the engine foward to the foward mount holes on the frame. This will put your engine in the correct v8 position, this looks better and gives you a extra inch between the firewall and distrbuter otherwise it will not allow you much clearence. do a search, this topic has been covered many times. __________________ 71 C10 SWB BLACK AND WHITE 350 CRATE TH350 ENJOY LIFE

08-19-2007, 08:07 PM	#3
71Rat ran out of money Join Date: Apr 2003 Location: northern, NJ Posts: 925	Re: swapping 250 for the 350; frame mounts the PO of my truck put a v-8 in the I-6 position, yeah it looks set back far but it doesnt have any problems Attached Images __________________ Modify everything, leave nothing alone!~

08-19-2007, 11:59 PM	#4
Brock upgrading to an older model Join Date: Aug 2007 Location: Sacramento, KY Posts: 346	Re: swapping 250 for the 350; frame mounts I'm gonna be doing the same thing except from a I-6 292 (doesn't run) to a 307. Are these the "towers" your refering to? http://cgi.ebay.com/ebaymotors/ws/eB...154172891&rd=1 I've read on here that you also need to move the mounts 3" forward to allow room for the distributer not to be cramped, is this right? I've got a brother-in-law that'll actually gonna do the swap (I'll be assisting) I just want to make sure we have all of the right parts and tricks. Last edited by Brock; 08-20-2007 at 12:00 AM.

08-20-2007, 12:08 AM	#5
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,684	Re: swapping 250 for the 350; frame mounts You CAN run a V-8 in the I-6 position without any problems. My 68 was like this for years until I started the rebuild. I even ran an HEI, installed with no problems. I am moving it into the V-8 position just because I can. __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE

08-20-2007, 12:29 AM	#6
Shane Account Suspended Join Date: Jun 2000 Location: over yonder Posts: 14,270	Re: swapping 250 for the 350; frame mounts glock is right ... you can run a small block on the I6 towers ... my '67 was that way when i got it and it ran fine.

08-20-2007, 01:22 AM	#7
Brock upgrading to an older model Join Date: Aug 2007 Location: Sacramento, KY Posts: 346	Re: swapping 250 for the 350; frame mounts Is there any mod needed down the line (drive shaft, rearend)? I'm going with a 700r4 from a 3-OTT __________________ 68 stepside, short-box, multi-colored (for now)

08-20-2007, 06:42 PM	#9
2bits Registered User Join Date: Jan 2006 Location: Dallas Posts: 504	Re: swapping 250 for the 350; frame mounts If you do the factory set up and move the engine forward, yes you will have all the stuff that goes along with it. Tranny lines will be too long, driveshaft will be too short, need to move the tranny crossmember, and the shifter linkage too. All the frame holes were pre-drilled from the factory on mine, so it was just a matter of moving everything and having the driveshaft re-done. I got some generic brake line from Oreillys for cheap and hand formed them as tranny lines. Attached Images __________________ _______________ Thomas '78 Silverado '74 Monte Carlo '47 Teardrop Trailer East Texas Classics Local Club



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