350 TBI to 454 TBI Conversion

[nomadman2001]

I am getting ready to upgrade my 350 TBI with a 454, also TBI. I want to retain the 700R4 trans which in my mind, is my biggest concern ECM-wise. I have searched and found others making this swap but with a TH400. Any advise would be appreciated. For those who may advise against keeping the 700R4 due to strength issues, I have built them before to withstand the TQ and HP of a big block.

[nomadman2001]

Perhaps that wasnt really a question. Presently running a 7747 ECU with prom code ASDU. Can I modify this bin or is there one that will run the 454 and continue to operate the TCC? The original ECU was a 16147060 with chip BANC

[Fast355]

I am getting ready to upgrade my 350 TBI with a 454, also TBI. I want to retain the 700R4 trans which in my mind, is my biggest concern ECM-wise. I have searched and found others making this swap but with a TH400. Any advise would be appreciated. For those who may advise against keeping the 700R4 due to strength issues, I have built them before to withstand the TQ and HP of a big block.

The 700r4 only uses the ECM to control the torque converter. Just copy over the settings from a 350/700r4 BIN file. That being said its not the HP that will kill the 700r4 its the torque. You could build the toughest 700r4 and unless the car is traction limited by narrow tires and low gearing the 700r4 will break. The other part that will be fun is the TV cable. A 454 TBI lacks a TV cable connection. My solution running one on a 350 was to use an edelbrock cruise control correction bracket for their 1400 series carb.

[nomadman2001]

Understand the torque concern. For right now it is what it is due to complications with other driveline parts. The TBI cable has been addressed by using the throttle arm from a 350 TB on the 454 TB and modding the cable bracket. As far as copying from a 350/700r4 BIN, where is that info location in the BIN file? Is there a GUI interface? I have not used the tuning software before. Thanks.

[nomadman2001]

NM. I see the sticky on the TP forum and am reading up on it - thanks.

[dave w]

This tread reminds of the "Worst Ever" TBI conversion I've ever seen.

Strike one - Don't use the SBC Throttle Body on a 454, sure the 700R4 TV linkage is on SBC Throttle Body.

Strike two - Don't use SBC injectors on a 454, sure the BPW is the same for both the 350 and 454 .bin files but the injector flow is not the same!

Strike three - So the decision was made to use a SBC Throttle Body on a 454 because it solves the 700R4 TV Cable linkage problem, but maybe an adjust the 700R4 TV cable is still needed? Maybe that's why the freshly rebuilt 700R4 only lasted 300 miles after the 454 conversion. Just because the 350 throttle body and 454 throttle body have the same bolt pattern does mean they are interchangeable.

I doubt the lean running / fuel starved 454 with 350 injectors was a "Torque Monster" capable of smoking the tires or burning 700R4 clutch packs.

I still wonder, why keep using the 350 PROM chip on a 454??? Oh, the 454 PROM chip was for a TH400, that why.

In this one special case, I didn't even need to power on my laptop to figure out what was wrong with the prom chip. I simply stated, a "For Sale" sign is your best option. A custom PROM chip is no longer needed.

dave w

[nomadman2001]

Ouch! Sorry if I wasnt clear. I am using the 454 2" bore TB with correct BBC injectors. I cut the arm off a 350 TB and replaced the one on the 454 TB. I modified the 454 throttle cable bracket to accept the TV cable in the correct location retaining the stock geometry. As far as the chip, i was asking what Bin to use for the 454 fuel/timing and retain TCC lockup.

[Fast355]

Ouch! Sorry if I wasnt clear. I am using the 454 2" bore TB with correct BBC injectors. I cut the arm off a 350 TB and replaced the one on the 454 TB. I modified the 454 throttle cable bracket to accept the TV cable in the correct location retaining the stock geometry. As far as the chip, i was asking what Bin to use for the 454 fuel/timing and retain TCC lockup.

The only 454/700r4 setups I know of were the first G-series vans with big blocks. No idea what BCC those used as there were not many of them.

[S.O.B.B.]

I had geometry problems on lwb Sammy that I converted to suburban drive line.because of the incorrect geometry it wasted the trans pretty quickly.after correcting it the next trans worked much better.I used a site called purple sage 700 r4 page.it has info about the tv cable and infomportance of proper adjustment.

[dave w]

This tread reminds of the "Worst Ever" TBI conversion I've ever seen.

Strike one - Don't use the SBC Throttle Body on a 454, sure the 700R4 TV linkage is on SBC Throttle Body.

Strike two - Don't use SBC injectors on a 454, sure the BPW is the same for both the 350 and 454 .bin files but the injector flow is not the same!

Strike three - So the decision was made to use a SBC Throttle Body on a 454 because it solves the 700R4 TV Cable linkage problem, but maybe an adjust the 700R4 TV cable is still needed? Maybe that's why the freshly rebuilt 700R4 only lasted 300 miles after the 454 conversion. Just because the 350 throttle body and 454 throttle body have the same bolt pattern does mean they are interchangeable.

I doubt the lean running / fuel starved 454 with 350 injectors was a "Torque Monster" capable of smoking the tires or burning 700R4 clutch packs.

I still wonder, why keep using the 350 PROM chip on a 454??? Oh, the 454 PROM chip was for a TH400, that why.

In this one special case, I didn't even need to power on my laptop to figure out what was wrong with the prom chip. I simply stated, a "For Sale" sign is your best option. A custom PROM chip is no longer needed.

dave w

This post Was Not directed at nomadman2001!

The title of this tread REMINDED ME of project I was asked to help with SEVERAL YEARS AGO!

I was hopeful others would benefit from the information I shared about a project that went sideways when replacing a 350 TBI engine with a 454 TBI engine.

I'll say it again, hoping to make my point 100% clear!! This post Was Not directed at nomadman2001!

dave w