Re: Install thread- Holley EFI Sniper on '72 402 big block
 

I think it's a surpise......lol

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

A sluggish 14.5 at 90mph. Something needs some adjusting.

If I left it in Drive, it'd do 14.7 at 88, shifting really early around 4000rpm. I tried tightening the TV cable to the 700R4. It didn't seem to make a difference.
Manually shifting from 1-2-3, I was able to make it shift around 5500rpm which netted the 14.5 at 90mph.

Traction was not an issue. I left as hard as I could which was at the 2,400rpm the converter would let me. 2.0 60' every time.

Possible reasons:
- engine is not making the claimed 430hp so some adjustments need to be made.
- trans is robbing the power somehow.

A fellow at the track said his friend has a TCI 700R4 and they had to change the 'module' to a corvette module and it solve the low rpm shift points. I'll look into it.

In case y'all think I need a 'driver mod', I've been drag racing for 20 years and am used to cutting 1.7# 60' times with manual transmission cars trapping 125mph.

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

Dyno should help you in that area, how did the sniper feel compared to your old carb setup, better response all around or is it still learning

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

Does installing the Holly system solve the fume issue from having the tank in the cab? Was it an issue for you before the install? Are you glad you left the tank in the cab, or would you recommend moving it to the rear? Thanks for any feedback you can provide.

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

I didn't have any fume issues with the in-cab tank while using a carb. There is still no fume issue now with the EFI. So far (500miles driving) I have had no issues using the in-cab tank with the EFI system. When I turn the key on and hear the pump prime, I can hear a little fuel coming from the return line into the tank, but it doesn't bother me and I can't hear it when the truck is running.

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

Thanks so much for the info. I'm trying to gather as much info as I can. Going to be installing a big block with the Holly Sniper system this coming winter.

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

How do you have the TV (Throttle Valve) cable for the 700r4 connected to the throttle linkage? Many folks think the TV cable is a "kick down" cable but it is not. The pull on the TV cable is very important in controlling the pressures with the transmission and most throttle linkages don't have the correct geometry, if it isn't pulled in the correct way it can at the very least make it operate poorly and at worst burn it up. I had my unit shipped from FiTech to Bowtie Overdrives to be modified to work with their "TV Made Easy" system and it works very well. I was just curious about how yours was configured and if that might play into your 1/4 mile time.

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

What a great thread. Thanks for sharing it all!

Re: Install thread- Holley EFI Sniper on '72 402 big block
 

Hey guys any update on this? I'm thinking of doing the Sniper kit and keeping the stock tank. Is there anything you would have changed or did differently now that you've been driving them for awhile? Thanks.