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2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Installing Hooker Headers this Wednesday
I think I have everything ready to install the headers day after tomorrow. I try do do as much as I can on my 71 but for this I need a lift and to weld so I have to got to a shop. I’ve had my 71 for 4 years now and have never left it at a shop, very nervous about it…🫣
A base 350 in 71 used the exhaust manifolds to bolt the Alternator and air compressor in place. I think it’s the only year they did that. Anyway since I’m changing the stock manifolds to headers I had to buy some new brackets that use the heads as the mounting points. In the instructions to mount the headers it says to use one inch bolts to secure the new brackets. Not sure if the brackets came with the bolts. I’ll check that today. Being in Spain I can’t run down to the parts store and get bolts, no one has USA hardware, it’s all metric here… that’s a bit of a worry. Also saw in the instructions I need to use a shorty oil filter, just happen to have one. But my big concern is also in the instructions it says the headers can’t be used with a Turbo 400 auto transmission which is what I have… When I bought the headers I specified my Vette had the original automatic transmission. The headers I bought are Hooker Header with Ceramic Coating part number HOK-2456-1HKR. Anyone ever try to install these with a turbo 400 transmission?
Yeah that document came packed in the box with the headers. I've been desperately trying to talk to some one from Hooker. All telefone numbers take you to Holley which is the company they are sold through. It’s impossible to get anyone on the phone there. I’ve tried 4 times each time waiting over 15 minutes on hold. I’m calling from Spain mind you… I paid well over 700€ with shipping and import taxes and they might just end up as wall art. I bought the headers a while back specifically for a 1971 base 350/270hp with power steering, air conditioning and power breaks. Told them my Vette was an automatic. Also had to buy new brackets for the alternator and air compressor as they both use the original manifolds to bolt on to…
Last edited by Daveinspain; Jun 20, 2023 at 04:11 AM.
Weird there is a note that says "Header dual system will not fit Turbo 400 applications". Hooker side exhaust & Corvettes has been around since the 70's and dumpster diving the internet there is no mention of this system not working on a C3 Corvette with TH400 transmission.
I did find a picture of a 72 chassis with automatic and Hooker Side Exhaust and I see no reason why any transmission be it manual or automatic would have any effect in installing the Hooker side exhaust header.
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Originally Posted by Mr D.
Weird there is a note that says "Header dual system will not fit Turbo 400 applications". Hooker side exhaust & Corvettes has been around since the 70's and dumpster diving the internet there is no mention of this system not working on a C3 Corvette with TH400 transmission.
I did find a picture of a 72 chassis with automatic and Hooker Side Exhaust and I see no reason why any transmission be it manual or automatic would have any effect in installing the Hooker side exhaust header.
yeah problem is mine are not side exhaust, mine are regular long tube headers that tie into the dual exhaust system…
You might consider selling them here on the forum, take the hit and purchase a set of new headers that will fit. I doubt Holley will issue you a credit. PIA for sure.
Good luck we all make mistakes in our purchases, I know I have.
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Originally Posted by caskiguy
You might consider selling them here on the forum, take the hit and purchase a set of new headers that will fit. I doubt Holley will issue you a credit. PIA for sure.
Good luck we all make mistakes in our purchases, I know I have.
yeah that’s an option but I’m in Spain so if I don’t get them on the Corvette they’ll be wall art for a while…. Although my mechanic says he wants to give it a go and see he can get them installed. I usually try to do the work myself but I don’t have a lift and don’t have welding equipment…
Last edited by Daveinspain; Jun 20, 2023 at 09:06 AM.
yeah that’s an option but I’m in Spain so if I don’t get them on the Corvette they’ll be wall art for a while…. Although my mechanic says he wants to give it a go and see he can get the installed. I usually try to do the work myself but I don’t have a lift and don’t have welding equipment…
It just occurred to me that a solution for your problem may be installing a Gforce crossmember (I may do the same but for other reasons) which give you a wider exit going past the TH400.
Your current crossmember is easily removable and the new just bolts right up. https://www.crossmembers.com
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Originally Posted by caskiguy
It just occurred to me that a solution for your problem may be installing a Gforce crossmember (I may do the same but for other reasons) which give you a wider exit going past the TH400.
Your current crossmember is easily removable and the new just bolts right up. https://www.crossmembers.com
First I need to see why they won’t work, where the problem is… Not sure how the crossmember will help me, plus it’s another 600€ if they ship to Spain…
Last edited by Daveinspain; Jun 20, 2023 at 09:34 AM.
That is really surprising, seeing as Hooker Super Comps (1 3/4" tubes) fit C3 Corvettes with no problems. I ran them for years on my '69 and I have a TH400 auto trans. Consider these.....https://www.summitracing.com/parts/h...ette/year/1969
Not sure how mechanically inclined you are, but if it was me, I would install the headers myself. That will allow you to figure out what the issue is with the headers, and obtain whatever hardware you require. If you ask a shop to do those things, you know they will be in a hurry, and you might not be happy with the results. I suspect you will find that the issue with the TH400 is relatively minor and can be resolved for less than the cost of a new set of headers.
Installing Hooker Headers this Wednesday
