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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: 1980 gold on January 11, 2012, 10:07:40 pm

Title: 87 sm 465 to turbo 400 swap
Post by: 1980 gold on January 11, 2012, 10:07:40 pm
so we did this swap this past week obviously changed to a flexplate used the t400 crossmember, made fluid lines, my stock radiator already had holes for fittings ( sorry my auto knowledge is not up to date i was told most of em do now), my stock driveshafts both worked perfectly and were the right length which was a good surprise. I used the b&m floorshifter for now until spring. it drives great shifts nice and tight although it stays in 2nd for a bit long i gotta see if shift points can be changed? not sure on that one. any ideas
Title: Re: 87 sm 465 to turbo 400 swap
Post by: Engineer on January 12, 2012, 05:46:46 pm
Check your governor pressure, and your modulator pressure.

The governor pressure over comes the modulator pressure to initiate an upshift. If you have too much modulator pressure it will give late upshifts.
Title: Re: 87 sm 465 to turbo 400 swap
Post by: 1980 gold on January 12, 2012, 06:39:47 pm
thanks its the screw under the hose on the modulator for adjustment?
Title: Re: 87 sm 465 to turbo 400 swap
Post by: Engineer on January 12, 2012, 08:54:35 pm
Assuming there is nothing wrong with your modulator, and you have the adjustable variety, you can try moving the adjustment screw to see if it changes your shift points.
Title: Re: 87 sm 465 to turbo 400 swap
Post by: 1980 gold on January 13, 2012, 08:59:31 pm
suddenly i am having trouble with this truck stalling when going from park to reverse even when warmed up and idling in park it cut out on me twice tonight but starts up again with no trouble whatya think?
Title: Re: 87 sm 465 to turbo 400 swap
Post by: 1980 gold on January 18, 2012, 03:59:41 pm
well i had the adjustable modulator shifting good now but still stalling from park to reverse and idling in park. Any ideas
Title: Re: 87 sm 465 to turbo 400 swap
Post by: Engineer on January 21, 2012, 09:02:49 pm
What is your idle speed?

You should be around 650~750 RPMs. I prefer a little more on an auto over a manual, but not so much that the trucks drives off with out using too much brake to hold it.