Hi all, I have been lurking for a few weeks looking over the threads getting a general idea about the performance modifications for the the Slant 225.

I have some questions specific to the 225 in a base model D100 with the 3 speed manual column shift. I believe the transmission model is the A230, is this correct? Does anyone have more info on the truck specific A230?

I found some gear ratios for the transmission and have some questions regarding the Clifford Performance products and how well they pair with the 3 speed manual.

I plan to keep the current transmission, build the truck to perform more efficiently with the HEI upgrade and to get the engine breathing better with the Weber carb, CP intake, header, exhaust etc.

The truck has 85K and seems well cared for on a farm. I want to build it 'Prerunner' style to haul motos and various items. I want to refresh the suspension, move to 31 AT tires.

Are the Clifford Performance products worthwhile with the base A230 3 speed or will it be a bottleneck with it's limited gearing? My interest with the Slant 6 is it's efficiency when modified, it's uncommon. Torque and better MPG are most important to me.

Also, I read that the 69' era 225 is rated for more power/torque. Is it worth locating one, rebuilding and then adding the CP products?

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1976 D100

Hello and welcome to the forum.

I can not answer, or provide any insight into the A230 Transmission..

As for Clifford performance, it is my understanding that they are less than ideal to do business with. The original owner passed away, and customer satisfaction is not high on the list of priorities now... Happily you can get what you need through various other suppliers. . and likely pay less for the item in the process.

Yes doing a tune up is a good idea. Checking valve lash, distributor re-curve, checking for timing chain elongation...

Have you found the engine build matrix? Aggressive Ted has his buildup on the first page, and he reported it was an excellent daily driver with very good economy.. Stock carb, and exhaust manifold, as both were not optimized from the factory. Yes a 2bbl intake and exhaust would help.. but the real bottleneck I believe is lack of compression, and intake/exhaust valve flow...and ignition timing curve that is more warranty prevention than optimized..

Think very carefully before you decide (not) to spend any money with Clifford. They have a long and ugly reputation for being a bunch of clowns; see for example here, here, here, here, and here. Much of what they sell is inaccurately described, and a lot of it is not even slightly cost-effective. The good news is that you don't need to go to Clifford to get hot rod parts for slant-6s; there are lots of other, better options. See for example Dutra Duals and header options discussed in this thread and this one, Erson custom cams, HEI ignition upgrade, Mike Jeffreys windage trays, Hurricane intakes, other exotic intakes. Hi-perf engine buildup here, high-perf parts and build info here.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Does it have a side cover or a top cover? During the mid 60's Ma Mopar also used the A-390 3 speed transmission... FYI. Is your starter mounted up close to the exhaust manifold or low near the ground?
They are no longer reputable and may not have the parts you need in stock, but they will take your money for a 'deposit'... the best bet is to run a parts wanted ad of what you need and keep an eye out on ebay and craigslist...
HEI upgrade = good
Recurving the distributor= good once you decide on a build and your drive train options...
Clifford Intake will be large and want a 4 barrel, the 2 barrel will be better matched to a super six intake or an offenhauser intake....
Truck Headers are specific and you will want to keep an eye out for a second hand Clifford set or look at other aftermarket companies...
Going to headers will require manifold heat if you plan on driving the truck during the fall and winter months...

Heavy vehicle, Larger tires and hauling/offroad will require better rear end gearing, something more like 3.55+ you will have to look at an online calculator to see what your rear ratio and tire size is compared to what you... you may want to move up to a HD manual transmission as well (something like the NP235/435), just putting that out there...
As stated you will have to think about your rear ratio, tire size, vehicle weight, etc... the 3 speed might bottle neck if it's not up to handling the mods you are wanting... if you have the 10" clutch it might be light for AT use...
This is a common misconception for people that don't understand how the industry moved away from Gross HP ratings to NET SAE HP ratings on engines about 1972... previously the 145 hp rating on the 225 in the 60's was due to how the readings are taken... 'gross' they could be an engine run without A/C, and alternator, power steering, etc... Net SAE is closer to reality with some of the accessories installed... putting the 145 gross closer to 115hp to 90 hp depending on the year and accessories tested with...

Moving to an RV cam, 9:1 static compression, 8:1 dynamic compression, OS valves, porting the head and freeing up some of the restrictions at the valve guide boss, small 4 barrel, stepping down to a set of better rear gears to offset the bigger tire size, etc...



There are a couple of other truck guys onsite that should be able to give you some specific directions on what they have successfully done to their rides.

Thank you for all the replies and advice.
A lot of solid info to digest and think through.

Spence

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1976 D100

My truck build is here:
http://slantsix.org/forum/viewtopic.php?t=56667

All in all I am extremely pleased with it. If I had a manual transmission I may have gone with a little bigger cam. Gets good mileage too with cruising gears.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Good thing is there are a few slanters and racers near you in the crossville and knoxville areas... many of them dont frequent this board however.


Good luck.


Greg

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http://www.youtube.com/hyperpack

Wow, very nice. This is the level I envision taking my build, but without a garage at the moment. I have yet to buy the truck and first wanted to see what was possible with the Slant 6 as I know aftermarket support is limited and even more so body wise. My first vehicle was my grandfather's 78' D100 with 318/727 and miss it sorely.

If the truck remains available in the next few weeks, I may pick it up and hang on to it until I can get a proper build going. I have a friend that wants to give me a M90 blower but it's the GM version. I did read Matt's thread on his blower build and it had me salivating.

I want to build the truck with a slight lift, all new suspension and just performing efficiently to haul moto's, hunt, haul and cruise the interstate without worrying about getting ran over.

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1976 D100