1995 Gen V 454 questions

[Kelly1966]

Ok Guys and Gals,

Looking for some opinions. I have a bone stock 45k mile 1995 454, was TPI, RV motor going in my 1968 GMC 1500 truck. I’m not racing it, might tow a little, other than that, nothing else but cruising. I have a set of headers, a Brodix Hv2016 intake, off the shelf Holley 3310-6 750 cfm carb.
That’s it, I was going to run it with my Saginaw 3 speed column shift but, as usual with project things change. I have a TH400 that I’m having rebuilt, stock converter and a 3:73 rear ratio. Pretty tight budget due to I upgraded all the suspension and went Disk brakes all Around. I have the correct Automatic Flywheel. So I guess my question is, is this a good setup or should I go a different route with the intake and headers? I got the intake in a trade, the carb I ran on my 427 for a bit and it worked well with that. Just kinda looking for suggestions with in my budget, I have no urge to cam it, put different heads our anything major, I just figured there is a wealth of good solid information I might put to use. Thanks for any input.

[PbFut]

With all that torque at hand the 3.73 rear end may be a bit low. Highway RPM is going to be a bit on the high side for a 1 to 1 3rd gear in the 400. Given you have so much grunt from the motor a 3.5 or even 3.08 will give you a nice cruise. Unless you are towing big weight I don't think the 3.73 torque multiplication is going to be usefull.

[Kelly1966]

Good point, the 3:73 (Factory) would make the former 307 rev a bit on the interstate. If I decide on doing more traveling to events, I will look into going to a taller gear. Where I am living is nothing but country roads and 55 mph max speed limits. I am still considering the intake as it is a duel plane with a 3500-6800 RPM range which is a bit out of my operating range, I’m going to try it and just see and if not trade it or source a good used one that’s will be more in how I’m planing on driving.

[truckster]

Are you sure the 454 wasn't throttle body injection? Those are really easy to set up and very reliable. If you have all the parts it would fit your needs perfectly.

[MARKDTN]

Originally Posted by truckster

Are you sure the 454 wasn't throttle body injection? Those are really easy to set up and very reliable. If you have all the parts it would fit your needs perfectly.

I would second that. GM TBI is very easy to set up and being a motorhome setup you already have a nice stand-alone style harness. If you plan no mods to the engine the TBI will do better than any carb as far as mileage and changes in weather conditions. You will need to add a O2 sensor bung on the header collector. The only other thing you may not have is a VSS signal which you can easily add a pulse generator on the speedometer output on the transmission.

[Kelly1966]

My mistake, it was a TBI, I have the intake (Which weighs a ton) and throttle body, harness was butchered and no computer, I have plans this winter to go with some fuel injection but haven’t put much research into it yet. With my LS motors I used the stock harnesses and computers that came from the donors and had to redo the fuel systems. I have heard good things about the Holley Terminators but really don’t think I need something on that level.

[MikeB]

Originally Posted by PbFut

With all that torque at hand the 3.73 rear end may be a bit low. Highway RPM is going to be a bit on the high side for a 1 to 1 3rd gear in the 400. Given you have so much grunt from the motor a 3.5 or even 3.08 will give you a nice cruise. Unless you are towing big weight I don't think the 3.73 torque multiplication is going to be usefull.

That's for sure! I can tell you that even with my truck's 3.08 gears, I always wish for lower revs at speeds above 65 mph. That's with a mild 350 and 29.5" tires.

With a 454, you could even get by with 2.73 gears. That's what I had for 5 years in an 82 C10 with a 350.

BTW, the Saginaw 3-speed came in 3 flavors. At least that was the case for my 82 truck. The version with the tallest first gear (lowest torque multiplication) was used behind 350s, but I don't think it could handle a 454's torque.

[MARKDTN]

Originally Posted by Kelly1966

My mistake, it was a TBI, I have the intake (Which weighs a ton) and throttle body, harness was butchered and no computer, I have plans this winter to go with some fuel injection but haven’t put much research into it yet. With my LS motors I used the stock harnesses and computers that came from the donors and had to redo the fuel systems. I have heard good things about the Holley Terminators but really don’t think I need something on that level.

If you can find a TBI van in a pick-a-part you can get a harness and ECM pretty inexpensively. The Van harness is almost stand-alone and has a long trunk length so it's easy to move the ECM inside. Then all you need is a PROM for a 454. New the harnesses are relatively cheap for a Painless or I found this one for even less.

https://affordable-fuel-injection.co...iring-harness/

[68Gold/white]

If it was mine, I'd be doing the carb deal, also.
There's a ton of folks here that can easily accomplish all the electrical needs of the electrical spectrum on the fuel injection end. I'm not one of them.

My question, is: how will you supply fuel to the engine? It will have to be an electric pump. The 95 454 likely has no provision for a mechanical pump. Even if it did, the cam wouldn't have a cam pushrod lobe on it...

[Kelly1966]

Well, funny story, I was in the middle of nowhere Kentucky and the fuel pumped went out, the only garage in the area had an electric fuel pump and I installed it in the shops lot, I never changed it out, I should put a regulator on it as it has no return and I don’t know what psi it is although I’m sure it’s not a lot (it fed a 2 bbl), the Holley will work good at 6.5 psi. This truck and I have been through a lot😂