302 to 400 swap, info needed. - Pirate4x4.Com : 4x4 and Off-Road Forum

redpitbull44 · 02-22-2007, 04:44 PM

A buddy of mine has a 73 F-250 w/ a 302, 4 speed tranny (T-18?), NP 205, and a Dana 70 rear and Dana 60 front. He has a 400 that he will be replacing the 302 with. The only problem is we haven't been able to find motor mounts to match up. Does anybody know what mounts from a stock 73 engine will work with the 400? Would we be able to use the mounts for a 400 on the mount towers in the 73?

Jrod-13 · 02-22-2007, 06:06 PM

one of my buddies did that swap last year, in a 83' bronco. It was as simple as removing the 302 bellhousing, and putting on the 400 bellhousing. The stock 78' F-250 motor mounts dropped right in the 302 slots with a little work of a prybar.

GMCTruxrule · 02-23-2007, 03:36 PM

The 400 was not an option in the 73 model year.
My advice would be to source a set of 351M/400 motor mounts, you can/should buy new...and a set of the actual motor mount brackets, the part that bolts to the engine crossmember from an '78/79 truck and start from there.

redpitbull44 · 02-24-2007, 09:10 PM

So basically what we're talking her is new motor mounts ~$30, then the cross member from a late 70s truck that has the 351m/400 in it... correct. Then pull the 302, and the mount its on, mock it all up with the tranny on the engine with the proper bell housing to see where the cross member needs to attach, maybe even have it attached to the engine during mock up? I mean, it should bolt on over the top flanges of the frame rails right? To be honest I haven't even looked at the truck yet. How strong is the possibility that we can use the cross member that the 302 is on right now? Man, its shitty because neither engine came stock in '73.

mj · 02-24-2007, 09:27 PM

try it and see
looks like jrod says it is a bolt in

02-22-2007, 06:06 PM	#2 (permalink)
Jrod-13 Registered User Join Date: Feb 2003 Member # 17313 Location: Tower, MN Posts: 2,794	one of my buddies did that swap last year, in a 83' bronco. It was as simple as removing the 302 bellhousing, and putting on the 400 bellhousing. The stock 78' F-250 motor mounts dropped right in the 302 slots with a little work of a prybar. __________________ A recent survay of over 1000 trailer parks in the southeast found the 350 chevy out numbered the mullet by nearly 4:1, draw your own conclusion.

02-23-2007, 03:36 PM	#3 (permalink)
GMCTruxrule Registered User Join Date: Aug 2005 Member # 51243 Location: Tropical Paradise Posts: 3,410	The 400 was not an option in the 73 model year. My advice would be to source a set of 351M/400 motor mounts, you can/should buy new...and a set of the actual motor mount brackets, the part that bolts to the engine crossmember from an '78/79 truck and start from there. __________________ [COLOR="Lime"][B]1999 Chevy K3500, 5.7/4L80E/14FF/stock/stock/stock[/B][/COLOR]

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02-24-2007, 09:27 PM	#5 (permalink)
mj Registered User Join Date: Oct 2000 Member # 1919 Location: BC Canada Posts: 7,547	try it and see looks like jrod says it is a bolt in