I have a 400 out of a 78 Blazer 4 bolt main truck motor pulled heads has dished pistons. has very low miles like 70000 also have a 90 iroc camaro 305 tpi motor with under 70k mi
I want to use the 400 shortblock and 305 heads and injection for a motor to put in my jeep. How will this work? will it rais comp. to much? what cam would work good in this combo?
The TPI setup doesn't really flow good enough for a 400. I mean you will have lots of low end torque but in the upper RPM range you won't have much.
Don't believe me? Drive the 305 with the TPI and matt the pedal. When you hit around 4000-4500 rpm you should feel it pull less.
Good news is you could run it if you don't plan on revving the motor high and expecting a ton of performance. However they do have aftermarket runners and plenums that will help the TPI out.
Agreed. The TPI barely flowed enough for a 305. Put it on a 400 and it might be good for a school bus that doesn't see any more than 3800 rpms. Same goes for the heads. Even aside from compression, the factory 305 TPI heads barely flowed enough to support 305 cubes. Vortecs flow about 50% more, and they're still a little small for a 400.
I would suggest skipping all the expensive porting and valve work required to get a 305 head to work and just get heads that work. The factory 400 heads will flow more than the 305s, and even so, anything will still be limited by the TPI's flow.
I have a 400 out of a 78 Blazer 4 bolt main truck motor pulled heads has dished pistons. has very low miles like 70000 also have a 90 iroc camaro 305 tpi motor with under 70k mi
I want to use the 400 shortblock and 305 heads and injection for a motor to put in my jeep. How will this work? will it rais comp. to much? what cam would work good in this combo?
I agree with what's been said - The 305 heads and TPI don't breath very well. If your looking for big HP there are better options, but what do you want to do with this Jeep? If rock crawling and trail rides are your plans it might not be a bad setup. Especially since you have everything already. It won't make power in the upper RPMs but will have good low RPM power and GREAT throttle response for working it through the tough spots on the trail. I had a truck with a stock TPI on a 383 and though it wouldn't impress anyone in a dyno room it was a true pleasure to drive on and off road!
I wanted the tpi because I am putting it in a Jeep and carbs don.t work well off camber. aftermarket FI is out of budjet. I also have a 93 caprice lt1 350 can I use that set of heads? or would that intake work with the tpi harness. I want more HP than the 305 has and realy like the 400 small block motors. was hoping to make the 400 work with the tpi
For off road this will be a great combo....Build it with the 305 heads and enjoy! Keep the cam small (around 210 - 220 @ .050) and you'll have have plenty of power for the trail and, did I mention, GREAT throttle response!
Says who? There are dozens of affordable carbs that will work at 40-degree angles... and if you're a real off-roader, you know that 40 degrees of angle is absolutely pro-only territory. If you're exceeding the limits of a carb in a jeep that can exceed 40 degrees of any angle, then you need to worry more about fuel tank pickups than EFI.
What would be a better set of inexpensive heads to mate the injection to the 400
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