Early to late LT5 parts compatibility - ZR-1 Net Registry Forums

pantera1683 · 12-30-2011

I am building a 402 for my 1994 using a 1990 block and complete 1990 heads sans cams. I would like to use as many parts from the 1994 as possible to complete the build. What parts from the 94 engine will not work on the 90 engine?

Thanks

Jagdpanzer · 12-30-2011

Here are are few items that come to mind:

Timing chain cover
Oil pan
Oil pan baffle
Oil pump suction tube & pickup
Oil pump

There could be more.

A26B · 12-30-2011

1. There is a difference between early and late cam sprockets, 1 flat early vs 2 flats late.

2. Along those lines, I would remove the center stud on the exhaust side of the cyl head & plug the hole.

3. The 94 injector housings will bolt on OK, but the 90 cyl heads have a 3/4" hole in the vent ports, where the 91-95 models have only about a 1/4" hole. You will need to install destructor plugs in the corresponding ports of the inj housings with a similar size hole. There is a good thread about this and I wrote a tech article for the HOTB newsletter. It may appear in the next issue.

4. Then there is the EGR system. If you can plug the 94 plenum & lose the rest of it.

pantera1683 · 12-30-2011

Okay

Quote:

Originally Posted by A26B

1. There is a difference between early and late cam sprockets, 1 flat early vs 2 flats late. Can I use my 94 cams in the 90 heads?

2. Along those lines, I would remove the center stud on the exhaust side of the cyl head & plug the hole. Plug it with what?

3. The 94 injector housings will bolt on OK, but the 90 cyl heads have a 3/4" hole in the vent ports, where the 91-95 models have only about a 1/4" hole. You will need to install destructor plugs in the corresponding ports of the inj housings with a similar size hole. There is a good thread about this and I wrote a tech article for the HOTB newsletter. It may appear in the next issue. Yeah, I was following that thread, just need to find those Dorman 550-011 plugs

4. Then there is the EGR system. If you can plug the 94 plenum & lose the rest of it.

A26B · 12-31-2011

1. There is a difference between early and late cam sprockets, 1 flat early vs 2 flats late.
Can I use my 94 cams in the 90 heads? Yes, with the same sprockets.

2. Along those lines, I would remove the center stud on the exhaust side of the cyl head & plug the hole. Plug it with what? 3/8"-16 x 1/2" long set screw, with Loctite 565 or equivilant sealant. Screw in until flush.

3. The 94 injector housings will bolt on OK, but the 90 cyl heads have a 3/4" hole in the vent ports, where the 91-95 models have only about a 1/4" hole. You will need to install destructor plugs in the corresponding ports of the inj housings with a similar size hole. There is a good thread about this and I wrote a tech article for the HOTB newsletter. It may appear in the next issue. Yeah, I was following that thread, just need to find those Dorman 550-011 plugs.

4. Then there is the EGR system. If you can plug the 94 plenum & lose the rest of it.

12-30-2011	#1
pantera1683 Join Date: Mar 2010 Location: Fort Worth, TX Posts: 391	Early to late LT5 parts compatibility I am building a 402 for my 1994 using a 1990 block and complete 1990 heads sans cams. I would like to use as many parts from the 1994 as possible to complete the build. What parts from the 94 engine will not work on the 90 engine? Thanks

12-30-2011	#2
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,651	Re: Early to late LT5 parts compatibility Here are are few items that come to mind: Timing chain cover Oil pan Oil pan baffle Oil pump suction tube & pickup Oil pump There could be more. __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

12-30-2011	#3
A26B Join Date: Dec 2003 Location: Arcadia, OK Posts: 3,404	Re: Early to late LT5 parts compatibility 1. There is a difference between early and late cam sprockets, 1 flat early vs 2 flats late. 2. Along those lines, I would remove the center stud on the exhaust side of the cyl head & plug the hole. 3. The 94 injector housings will bolt on OK, but the 90 cyl heads have a 3/4" hole in the vent ports, where the 91-95 models have only about a 1/4" hole. You will need to install destructor plugs in the corresponding ports of the inj housings with a similar size hole. There is a good thread about this and I wrote a tech article for the HOTB newsletter. It may appear in the next issue. 4. Then there is the EGR system. If you can plug the 94 plenum & lose the rest of it. __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

12-31-2011	#5
A26B Join Date: Dec 2003 Location: Arcadia, OK Posts: 3,404	Re: Early to late LT5 parts compatibility 1. There is a difference between early and late cam sprockets, 1 flat early vs 2 flats late. Can I use my 94 cams in the 90 heads? Yes, with the same sprockets. 2. Along those lines, I would remove the center stud on the exhaust side of the cyl head & plug the hole. Plug it with what? 3/8"-16 x 1/2" long set screw, with Loctite 565 or equivilant sealant. Screw in until flush. 3. The 94 injector housings will bolt on OK, but the 90 cyl heads have a 3/4" hole in the vent ports, where the 91-95 models have only about a 1/4" hole. You will need to install destructor plugs in the corresponding ports of the inj housings with a similar size hole. There is a good thread about this and I wrote a tech article for the HOTB newsletter. It may appear in the next issue. Yeah, I was following that thread, just need to find those Dorman 550-011 plugs. 4. Then there is the EGR system. If you can plug the 94 plenum & lose the rest of it. __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.