67 427/400 Thermostat Housing Bolt length?

[Pete NCRS # 30998]

Got a thermostat housing bolt kit with the "TR" head stamp for my 67 427/400 Vette.

The short bolt has the standard metal/chrome finish and the long bolt has a light yellow finish.

My questions>

1. is the color combination correct?

2. When I installed the long bolt it seem to be a 1/2" too long. What is the correct bolt lenght for the 6 427/400 Vette with the part # 3877660 thermostat housing? The lenght of the long bolt as pictued below is 2 1/2" over all lenght and 2 1/4" threaded.

Thanks in advance for any help.
Pete

[Rob A.]

Re: 67 427/400 Thermostat Housing Bolt length?

It sounds like one is "zinc" and the other, more yellow one,"cad" plated. Paragon indicates in their catalogue that the one they offer, which I believe is "TR" headmarked, needs to be cut shorter. When I installed it in my '67, 400 thermostat housing I cut it down as recommended.

[Rob A.]

Re: 67 427/400 Thermostat Housing Bolt length?

Pete,

Short of replating or replacing one of the bolts to match the other, try softening the brightness of the one with fine, steel wool. Try it on the threads where it won't show if you're not happy with the results.

[Pete NCRS # 30998]

Re: 67 427/400 Thermostat Housing Bolt length?

Hi Rob, I checked paragons catalog and here is what it says>

PR #: 721K
Water outlet attaching bolt kit, “TR” headmark, (1) 3/8-16x2 3/4", (1) 3/8-16x11/8".
1955-57 w/1x4.
1958-65 All 283 and 327 exc. Sp.Hi.Perf. and 396.
1966-67 w/327 Sp.Hi.Perf.
-Note: When using with outlet #3711268, it will be necessary to cut 5/16" from threaded end of long bolt. Also correct for Pontiac with V-8 engines.

For Years:1955 to 1967
Packaging: Kit
Condition: New
Type: Stock

It doesn't even list the 427/400 engines for those bolts.

Thanks,
Pete

[Rob A.]

Re: 67 427/400 Thermostat Housing Bolt length?

Pete,

Sorry, you're right, it looks like it should already be the correct length. I do remember cutting the one I used shorter. It was a "TR" marked bolt as well, and I do think I got it from Paragon.