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i300 low top speed

tedrow42

Missouri Chapter member
Ok so I'm at work on the boat and the guy I got workin on my truck told my mom that it won't go over around 50 mom can't remember what all he said about it... its a 4 speed 4x4 and I'm thinkin its got 4.10 axals or somewhere in that ballpark

I didn't drive it but 3 miles on a backroad and my 80 I don't remember being very fast eather same drive line exept 1/2 ton the 86 is a 3/4 ton

Can some one tell me if its the gearing which is what I think or if there could be a problem doesn't smoke or have a problem fireing
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
That set up should be able to hit hwy speeds no problem...it won't be fast, but it should be able to get there. 4.10's aren't an overly aggressive gear for that rig, 5.13's...probably hamper the top speed, but I don't believe the 4.10's are an issue.

My first areas of concern would be compression on all cylinders...the original 351M in my Bronco had zero comp on 3 cylinders and couldn't push itself over a parking lot curb. I'd also check for any brake hang up...easy way to do it borrow a 'laser thermometer', drive around for a bit...point the thermometer at all 4 corners, the one with excessive heat is the hang up.
 

Fellro

Moderator
Staff member
I would also consider fuel filter, if it is partially plugged, you won't be able to go real well either. Once the fuel supply runs short, the motor won't pull any more, but will run on a partial plug. I have had plenty of trucks with 4.10 gears and go down the road much more than 50...
 

Beach66Bum

Moderator
Top Poster Of Month
Hi tedrow42, my truck has the 351W with t-18 trans and 4.10's. I have no problem hitting 80mph on the highway, but remember these trucks are not designed for that type of speed! A short burst, that's it, and the tach will be up there at over 3000rpm! The factory fuel filter and pump are more than good for the stock engine, and I've pulled up to 4000rpm's in second with no fuel starvation. Must be fuel related, like Fellro stated
 

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